Laminated glass intermediate film and laminated glass

ABSTRACT

Provided is an interlayer film for laminated glass with which the sound insulating properties of laminated glass can be enhanced. The interlayer film for laminated glass according to the present invention has a one-layer structure or a two or more-layer structure, and includes a first layer having a glass transition temperature in dynamic viscoelasticity measurement of −30° C. or more and 10° C. or less, and when a glass transition temperature in unit ° C. of the first layer is referred to as Tg, a loss tangent tan δ of the first layer at Tg satisfies both of the following formula (1) and formula (2): 
       (Loss tangent tan δ of the first layer at  Tg )≥1.55  (1)
 
       (Loss tangent tan δ of the first layer at  Tg )= A ×(first storage modulus  G ′ of the first layer at  Tg −10° C./second storage modulus  G ′ of the first layer at  Tg +10° C.)+ B   (2)
         in the above formula (2), A is 0.003 or more and 0.04 or less, and B is 0.7 or more and 1.4 or less.

TECHNICAL FIELD

The present invention relates to an interlayer film for laminated glasswhich is used for obtaining laminated glass. Moreover, the presentinvention relates to laminated glass prepared with the interlayer filmfor laminated glass.

BACKGROUND ART

Since laminated glass generates only a small amount of scattering glassfragments even when subjected to external impact and broken, thelaminated glass is excellent in safety. As such, the laminated glass iswidely used for automobiles, railway vehicles, aircraft, ships,buildings and the like. The laminated glass is produced by sandwichingan interlayer film for laminated glass between two glass plates.

Examples of the interlayer film for laminated glass include asingle-layered interlayer film having a one-layer structure and amulti-layered interlayer film having a two or more-layer structure.

As an example of the interlayer film for laminated glass, the followingPatent Document 1 discloses a sound insulating layer including 100 partsby weight of a polyvinyl acetal resin with an acetalization degree of 60to 85% by mole, 0.001 to 1.0 part by weight of at least one kind ofmetal salt among an alkali metal salt and an alkaline earth metal salt,and a plasticizer in an amount greater than 30 parts by weight. Thissound insulating layer can be used alone as a single-layered interlayerfilm.

Furthermore, the following Patent Document 1 also describes amulti-layered interlayer film in which the sound insulating layer andanother layer are layered. Another layer to be layered with the soundinsulating layer includes 100 parts by weight of a polyvinyl acetalresin with an acetalization degree of 60 to 85% by mole, 0.001 to 1.0part by weight of at least one kind of metal salt among an alkali metalsalt and an alkaline earth metal salt, and a plasticizer in an amount of30 parts by weight or less.

The following Patent Document 2 discloses an interlayer film which isconstituted of a polymer layer having a glass transition temperature of33° C. or more.

RELATED ART DOCUMENTS Patent Documents

Patent Document 1: JP 2007-070200 A

Patent Document 2: US 2013/0236711 A1

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

For achieving comfortable driving of automobile, it is desired to reducein-car noises. Examples of the in-car noises include noises by enginedrive, noises caused by the tread patterns of the tires on travelling,noises by vibrations of the chassis on travelling, noises by vibrationsof the suspensions on travelling, noises by wind on travelling and thelike. Against such noises, it is desired to improve the sound insulatingproperties in the medium frequency range of from 2000 Hz to 4000 Hz ofthe laminated glass.

Also, in recent years, shifting of fuel automobiles powered by aninternal combustion engine to electric automobiles has been advanced.Examples of the electric automobiles include electric automobilespowered by an electric motor, hybrid electric automobiles powered by aninternal combustion engine and an electric motor, and the like. Inelectric automobiles, noises in the high frequency range exceeding 4000Hz are generated by the drive of the electric motor. In electricautomobiles, it is desired to improve the sound insulating properties ofthe laminated glass in the high frequency range exceeding 4000 Hz. Alsoin fuel automobiles powered by an internal combustion engine, it isdesired that the laminated glass have excellent sound insulatingproperties in the high frequency range exceeding 4000 Hz.

Also in laminated glass used in a construction or the like, it isdesired that the laminated glass have excellent sound insulatingproperties in the middle to high frequency range.

However, in laminated glass using the conventional interlayer film asdescribed in Patent Documents 1, 2, the sound insulating propertiescannot be increased sufficiently.

In recent years, as the performance of an electric automobile improves,the cruising distance increases, and the automobile becomes able todrive at higher speed. The improvement in the performance of an electricautomobile is expected to be further advanced from now on. It isexpected that effective reduction in noises by laminated glass enablemore comfortable driving in long-time driving and high-speed driving ofan electric automobile.

An object of the present invention is to provide an interlayer film forlaminated glass with which the sound insulating properties can beenhanced. Moreover, the present invention is also aimed at providinglaminated glass prepared with the interlayer film for laminated glass.

Means for Solving the Problems

According to a broad aspect of the present invention, there is providedan interlayer film for laminated glass (hereinafter, sometimes describedas an interlayer film) having a one-layer structure or a two ormore-layer structure, the interlayer film including a first layer havinga glass transition temperature in dynamic viscoelasticity measurement of−30° C. or more and 10° C. or less, a loss tangent tan δ of the firstlayer at Tg satisfying both of the following formula (1) and formula (2)when a glass transition temperature in unit ° C. of the first layer isreferred to as Tg, storage modulus G′ of the first layer at Tg−10° C. isreferred to as first storage modulus G′, and storage modulus G′ of thefirst layer at Tg+10° C. is referred to as second storage modulus G′ indynamic viscoelasticity measurement of the first layer.

(Loss tangent tan δ of the first layer at Tg)≥1.55  (1)

(Loss tangent tan δ of the first layer at Tg)=A×(first storage modulusG′/second storage modulus G′)+B  (2)

In the above formula (2), A is 0.003 or more and 0.04 or less, and B is0.7 or more and 1.4 or less.

In a specific aspect of the interlayer film according to the presentinvention, the first layer contains a compound having a softening pointof 70° C. or more and 200 or less.

In a specific aspect of the interlayer film according to the presentinvention, the first layer contains a thermoplastic resin, or contains acured product of a photocurable compound or a moisture-curable compound.

In a specific aspect of the interlayer film according to the presentinvention, the interlayer film is an interlayer film for laminated glasshaving a two or more-layer structure, the interlayer film includes asecond layer, and the second layer is arranged on a first surface sideof the first layer.

In a specific aspect of the interlayer film according to the presentinvention, the interlayer film is an interlayer film for laminated glasshaving a three or more-layer structure, the interlayer film includes athird layer, and the third layer is arranged on a second surface side atthe opposite side of the first surface of the first layer.

In a specific aspect of the interlayer film according to the presentinvention, the first layer contains a thermoplastic resin or contains acured product of a curable compound having a (meth)acryloyl group, thesecond layer contains a thermoplastic resin, and the third layercontains a thermoplastic resin.

In a specific aspect of the interlayer film according to the presentinvention, the first layer contains the thermoplastic resin, thethermoplastic resin in the first layer is a polyvinyl acetal resin, thethermoplastic resin in the second layer is a polyvinyl acetal resin, andthe thermoplastic resin in the third layer is a polyvinyl acetal resin.

In a specific aspect of the interlayer film according to the presentinvention, the first layer contains a plasticizer, the second layercontains a plasticizer, and the third layer contains a plasticizer.

According to a broad aspect of the present invention, there is provideda laminated glass including a first lamination glass member, a secondlamination glass member, and the interlayer film for laminated glassdescribed above, the interlayer film for laminated glass being arrangedbetween the first lamination glass member and the second laminationglass member.

Effect of the Invention

The interlayer film for laminated glass according to the presentinvention has a one-layer structure or a two or more-layer structure.The interlayer film for laminated glass according to the presentinvention includes a first layer having a glass transition temperaturein dynamic viscoelasticity measurement of −30° C. or more and 10° C. orless. In the interlayer film for laminated glass according to thepresent invention, in dynamic viscoelasticity measurement of the firstlayer, a loss tangent tan δ of the first layer at the glass transitiontemperature Tg of the first layer satisfies both the formula (1) and theformula (2). Since the interlayer film for laminated glass according tothe present invention has the configuration as described above, it ispossible to enhance the sound insulating properties of the laminatedglass prepared with the interlayer film for laminated glass according tothe present invention.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a sectional view schematically showing an interlayer film forlaminated glass in accordance with a first embodiment of the presentinvention.

FIG. 2 is a sectional view schematically showing an interlayer film forlaminated glass in accordance with a second embodiment of the presentinvention.

FIG. 3 is a sectional view schematically showing an example of laminatedglass prepared with the interlayer film for laminated glass shown inFIG. 1.

FIG. 4 is a sectional view schematically showing an example of laminatedglass prepared with the interlayer film for laminated glass shown inFIG. 2.

MODE(S) FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail.

The interlayer film for laminated glass according to the presentinvention (hereinafter, sometimes described as interlayer film) has aone-layer structure or a two or more-layer structure. The interlayerfilm according to the present invention may have a one-layer structureor may have a two or more-layer structure. The interlayer film accordingto the present invention may have a two-layer structure or may have athree or more-layer structure. The interlayer film according to thepresent invention may be an interlayer film having a one-layer structureprovided with only a first layer (single-layered interlayer film) or maybe an interlayer film having two or more-layer structure provided with afirst layer and other layer (multi-layered interlayer film).

The interlayer film according to the present invention includes a firstlayer.

Dynamic viscoelasticity measurement of the first layer of the interlayerfilm according to the present invention is carried out. In thismeasurement, a glass transition temperature in unit ° C. of the firstlayer is referred to as Tg, storage modulus G′ of the first layer atTg−10° C. is referred to as first storage modulus G′ (hereinafter,sometimes described as G′(Tg−10° C.)), and storage modulus G′ of thefirst layer at Tg+10° C. is referred to as second storage modulus G′(hereinafter, sometimes described as G′ (Tg+10° C.)). In the interlayerfilm according to the present invention, loss tangent tan δ of the firstlayer at Tg of the first layer (hereinafter, sometimes described as tanδ(Tg)) satisfies both the formula (1) and the formula (2).

(Loss tangent tan δ of the first layer at Tg)≥1.55  (1)

(Loss tangent tan δ of the first layer at Tg)=A×(first storage modulusG′/second storage modulus G′)+B  (2)

In the above formula (2), A is 0.003 or more and 0.04 or less, and B is0.7 or more and 1.4 or less.

The formulas (1) and (2) can also be expressed by the following formula(1A) and formula (2A), respectively.

tan δ(Tg)≥1.55  (1A)

tan δ(Tg)=A×(G′(Tg−10° C.)/G′(Tg+10° C.))+B  (2A)

In the formula (2A), A is 0.003 or more and 0.04 or less, and B is 0.7or more and 1.4 or less.

Since the interlayer film according to the present invention has theconfiguration as described above, it is possible to enhance the soundinsulating properties of the laminated glass prepared with theinterlayer film according to the present invention. In the presentinvention, for example, it is possible to enhance the sound insulatingproperties at 20° C.

Further, since the interlayer film according to the present inventionhas the configuration as described above, it is possible to enhance boththe sound insulating properties in the middle frequency range at about3150 Hz within the range of 2000 to 4000 Hz and the sound insulatingproperties at about 6300 Hz in the high frequency range exceeding 4000Hz of the laminated glass prepared with the interlayer film according tothe present invention.

From the viewpoint of further enhancing the sound insulating properties,in the formula (1), tan δ (Tg) of the first layer is preferably 1.8 ormore, more preferably 2.0 or more, further preferably 2.5 or more,especially preferably 3.0 or more. The upper limit of tan δ (Tg) of thefirst layer at the glass transition temperature Tg of the first layer isnot particularly limited.

From the viewpoint of further enhancing the sound insulating properties,A in the formulas (2) and (2A) is preferably 0.004 or more, morepreferably 0.005 or more.

From the viewpoint of further enhancing the sound insulating properties,B in the formulas (2) and (2A) is preferably 0.75 or more, morepreferably 0.8 or more, and is preferably 1.35 or less, more preferably1.3 or less.

As a method for satisfying the formulas (1), (1A), (2) and (2A), forexample, a method of increasing the molecular motion in the vicinity ofthe glass transition temperature in the first layer is conceivable. Themolecular motion may be increased before the glass transitiontemperature in the first layer, or the molecular motion may be increasedafter the glass transition temperature. For example, it is conceivablethat by making a molecule such as a high molecule be difficult to bebent in the vicinity of the glass transition temperature of the firstlayer, the molecular motion increases. Specifically, for example, whenthe first layer contains a resin such as a thermoplastic resin, acompound that gives strong interaction with the resin in the vicinity ofthe glass transition temperature of the first layer (for example, thelater-described compound (A)) can be added to the first layer. It issupposed that the above-described compound act on the resin, making themolecular motion more easy to occur. For example, when the first layercontains a resin such as a thermoplastic resin, it is supposed thatmolecular motion become more easy to occur by using a resin having abackbone with which large molecular motion is easy to occur in thevicinity of the glass transition temperature of the first layer.

Regarding the multi-layered interlayer film, viscoelasticity may bemeasured by using the first layer before lamination used for obtainingan interlayer film. In the multi-layered interlayer film, the secondlayer (and other layer such as the third layer) is peeled off from thefirst layer to take out the first layer, and viscoelasticity may bemeasured using the taken out first layer.

The first layer can be taken out from the multi-layered interlayer filmin the following manner.

The multi-layered interlayer film is stored in an environment at roomtemperature 23±2° C., relative humidity 25±5% for 1 month. Then in anenvironment at room temperature 23° C.±2° C., the second layer (andother layer such as the third layer) is removed from the interlayer filmby peeling off, to obtain the first layer. The obtained first layer ispress molded at 150° C. so that the thickness is 0.35 mm (at 150° C.without pressurization for 10 minutes, at 150° C. under pressurizationfor 10 minutes) to prepare a resin film. When the first layer isdifficult to be peeled off, the resin film may be prepared from theresin composition obtained by chipping off the first layer with aspatula or the like.

Hereinafter, specific embodiments of the present invention will bedescribed with reference to the drawings.

FIG. 1 schematically shows an interlayer film for laminated glass inaccordance with a first embodiment of the present invention as asectional view.

An interlayer film 11 shown in FIG. 1 is a multi-layered interlayer filmhaving a two or more-layer structure. The interlayer film 11 is used forobtaining laminated glass. The interlayer film 11 is an interlayer filmfor laminated glass. The interlayer film 11 is provided with a firstlayer 1, a second layer 2 and a third layer 3. The second layer 2 isarranged on a first surface 1 a of the first layer 1 to be layeredthereon. The third layer 3 is arranged on a second surface 1 b at theopposite side of the first surface 1 a of the first layer 1 to belayered thereon. The first layer 1 is an intermediate layer. Each of thesecond layer 2 and the third layer 3 is a protective layer and is asurface layer in the present embodiment. The first layer 1 is arrangedbetween the second layer 2 and the third layer 3 to be sandwichedtherebetween. Accordingly, the interlayer film 11 has a multilayerstructure (second layer 2/first layer 1/third layer 3) in which thesecond layer 2, the first layer 1, and the third layer 3 are layered inthis order.

In this connection, other layers may be arranged between the secondlayer 2 and the first layer 1 and between the first layer 1 and thethird layer 3, respectively. It is preferred that the second layer 2 andthe first layer 1, and the first layer 1 and the third layer 3 bedirectly layered. Examples of another layer include a layer containingpolyethylene terephthalate or the like.

FIG. 2 shows an interlayer film for laminated glass in accordance with asecond embodiment of the present invention schematically represented asa sectional view.

An interlayer film 11A shown in FIG. 2 is a single-layered interlayerfilm having a one-layer structure. The interlayer film 11A is singlyconstituted by a first layer. The interlayer film 11A is used forobtaining laminated glass. The interlayer film 11A is an interlayer filmfor laminated glass.

Hereinafter, the details of the first layer, the second layer and thethird layer which constitute the interlayer film according to thepresent invention, and the details of each ingredient contained in thefirst layer, the second layer and the third layer will be described.

(Resin)

It is preferred that each of the first layer, the second layer, and thethird layer contain a resin. One kind of the resin may be used alone,and two or more kinds thereof may be used in combination.

Examples of the resin include thermosetting resins and thermoplasticresins. The resin may be a cured product of a photocurable compound or amoisture-curable compound. The cured product of a photocurable compoundor a moisture-curable compound can be a thermoplastic resin.

The thermoplastic resin means a resin that softens and exhibitsplasticity when it is heated, and hardens when it is cooled to roomtemperature. Among the thermoplastic resins, especially thethermoplastic elastomer means a resin that softens and exhibitsplasticity when it is heated, and hardens to exhibits rubber elasticitywhen it is cooled to room temperature (25° C.).

Examples of the thermoplastic resin include a polyvinyl acetal resin, apolyester resin, an aliphatic polyolefin, polystyrene, an ethylene-vinylacetate copolymer resin, an ethylene-acrylic acid copolymer resin, apolyurethane resin, an ionomer resin, a polyvinyl alcohol resin, and apolyvinyl acetate resin. Thermoplastic resins other than these may beused. The polyoxymethylene (or polyacetal) resin is included in thepolyvinyl acetal resin.

The thermoplastic resins exemplified above can be a thermoplasticelastomer by adjusting the molecular structure, the polymerizationdegree and the like of the resin.

The resin is preferably a thermoplastic resin, more preferably apolyvinyl acetal resin, a polyester resin or polyvinyl acetate, furtherpreferably a polyvinyl acetal resin or a polyester resin, and thepolyvinyl acetal resin is especially preferably a polyvinyl butyralresin.

It is preferred that the first layer contain a thermoplastic resin(hereinafter, sometimes described as a thermoplastic resin (1)), orcontain a cured product of a photocurable compound or a moisture-curablecompound (hereinafter, sometimes described as a cured product (1)). Thethermoplastic resin (1) and the cured product (1) are collectivelycalled a resin (1). The first layer may contain the thermoplastic resin(1), or may contain a cured product of a photocurable compound or amoisture-curable compound. It is preferred that the first layer containas the thermoplastic resin (1), a polyvinyl acetal resin (hereinafter,sometimes described as a polyvinyl acetal resin (1)) or a polyesterresin (hereinafter, sometimes described as a polyester resin (1)). It ispreferred that the second layer contain a thermoplastic resin(hereinafter, sometimes described as a thermoplastic resin (2)). It ispreferred that the second layer contain a polyvinyl acetal resin(hereinafter, sometimes described as a polyvinyl acetal resin (2)) asthe thermoplastic resin (2). It is preferred that the third layercontain a thermoplastic resin (hereinafter, sometimes described as athermoplastic resin (3)). It is preferred that the third layer contain apolyvinyl acetal resin (hereinafter, sometimes described as a polyvinylacetal resin (3)) as the thermoplastic resin (3). One kind of each ofthe thermoplastic resin (1), the thermoplastic resin (2) and thethermoplastic resin (3) may be used alone, and two or more kinds thereofmay be used in combination. The thermoplastic resin (1), thethermoplastic resin (2), and the thermoplastic resin (3) may be the sameor different from one another.

The photocurable compound or the moisture-curable compound is preferablya curable compound having a (meth)acryloyl group, and is more preferablya (meth)acryl polymer. The resin is preferably a curable compound havinga (meth)acryloyl group, and is more preferably a (meth)acryl polymer.

It is preferred that the (meth)acryl polymer be a polymer of apolymerizable composition containing a curable compound having a(meth)acryloyl group. The polymerizable composition contains apolymerizable component. In order to effectively form the cured productin the layer containing the cured product, the polymerizable compositionmay contain a photoreaction initiator. The polymerizable composition maycontain an auxiliary for accelerating the curing reaction together withthe photoreaction initiator. Representatives of the curable compoundhaving a (meth)acryloyl group include (meth)acrylic ester. It ispreferred that the (meth)acrylic polymer be a poly(meth)acrylic ester.

For effectively obtaining the effect of the present invention, it ispreferred that the polymerizable component include a (meth)acrylic esterhaving a cyclic ether structure, a (meth)acrylic ester having anaromatic ring, a (meth)acrylic ester having a polar group, or an acyclic(meth)acrylic ester having 6 or less carbon atoms in the side chain. Byusing such a preferred (meth)acrylic ester, it is possible to enhanceboth the sound insulating properties and the foam suppressing propertiesin good balance.

Examples of the (meth)acrylic ester having a cyclic ether structureinclude glycidyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate glycidylether, 3-hydroxypropyl (meth)acrylate glycidyl ether, 4-hydroxybutylacrylate glycidyl ether, 5-hydroxypentyl (meth)acrylate glycidyl,6-hydroxyhexyl (meth)acrylate glycidyl ether;(3-methyloxetane-3-yl)methyl (meth)acrylate,(3-propyloxetane-3-yl)methyl (meth)acrylate, (3-ethyloxetane-3-yl)methyl(meth)acrylate, (3-butyloxetane-3-yl)methyl (meth)acrylate,(3-ethyloxetane-3-yl)ethyl (meth)acrylate, (3-ethyloxetane-3-yl)propyl(meth)acrylate, (3-ethyloxetane-3-yl)butyl (meth)acrylate,(3-ethyloxetane-3-yl)pentyl (meth)acrylate, (3-ethyloxetane-3-yl)hexyl(meth)acrylate; tetrahydrofurfuryl (meth)acrylate, γ-butyrolactone(meth)acrylate, (2,2-dimethyl-1,3-dioxolane-4-yl)methyl (meth)acrylate,(2-methyl-2-ethyl-1,3-dioxolane-4-yl)methyl (meth)acrylate,(2-methyl-2-isobutyl-1,3-dioxolane-4-yl)methyl (meth)acrylate,(2-cyclohexyl-1,3-dioxolane-4-yl)methyl (meth)acrylate,tetrahydrofurfuryl alcohol acrylic acid multimer ester;tetrahydro-2H-pyran-2-yl-(meth)acrylate,2-{1-[(tetrahydro-2H-pyran-2-yl)oxy]-2-methylpropyl}(meth)acrylate,cyclic trimethylol propane formal acrylate, (meth)acryloyl morpholineand the like. From the viewpoint of effectively obtaining the effect ofthe present invention, tetrahydrofurfuryl (meth)acrylate, or cyclictrimethylol propane formal acrylate is especially preferred.

Examples of the (meth)acrylic ester having an aromatic ring includebenzyl acrylate, phenoxypolyethyleneglycol acrylate and the like.

Examples of the (meth)acrylic ester having a polar group include(meth)acrylic esters having a hydroxyl group, an amide group, an aminogroup, an isocyanate group or the like as the polar group.

Examples of the (meth)acrylic ester having a hydroxyl group include2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate and thelike.

Examples of the (meth)acrylic ester having an amide group includeN,N-dimethylaminopropyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide,(meth)acryloyl morpholine, N-isopropyl (meth)acrylamide, N-hydroxyethyl(meth)acrylamide and the like.

Examples of the (meth)acrylic ester having an amide group or an aminogroup include N-dialkylaminoalkyl (meth)acrylamide,N,N-dialkylaminoalkyl (meth)acrylamide and the like.

Examples of the (meth)acrylic ester having an isocyanate group includetriallylisocyanurate, derivatives thereof and the like.

The above-described (meth)acrylic ester may be a polycarboxylic esterhaving a (meth)acryloyl group. Examples of the polycarboxylic esterhaving a (meth)acryloyl group include 2-acryloyloxyethyl succinate andthe like.

From the viewpoint of effectively obtaining the effect of the presentinvention, a (meth)acrylic ester having a hydroxyl group is preferred,and 2-hydroxyethyl (meth)acrylate, or hydroxypropyl (meth)acrylate isespecially preferred.

Examples of the acyclic (meth)acrylic ester having 6 or less carbonatoms in the side chain include methyl (meth)acrylate, ethyl(meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate and thelike.

For effectively obtaining the effect of the present invention, it ispreferred that the blending amount of the acyclic (meth)acrylic esterhaving 8 or more carbon atoms in the side chain in 100% by weight of thepolymerizable component be less than 20% by weight.

Examples of the (meth)acrylic ester include besides the compounds asrecited above, diethyleneglycol monoethylether (meth)acrylate, isobornyl(meth)acrylate, 3-methoxybutyl (meth)acrylate,2-acryloyloxyethyl-2-hydroxypropylphthalate,2-acryloyloxyethyl-2-hydroxylpropylphthalate, cyclohexyl (meth)acrylate;ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate,tetraethylene glycol di(meth)acrylate, 1,6-hexane diol di(meth)acrylate,1,9-nonane diol di(meth)acrylate, polytetramethylene glycoldi(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,3-butylene glycoldi(meth)acrylate, 2,2-bis[4-(acryloxyethoxy)phenyl]propanedi(meth)acrylate; trimethylolpropane tri(meth)acrylate, pentaerythritoltri(meth)acrylate, pentaerythritol tetra(meth)acrylate,dipentaerythritol penta(meth)acrylate, dipentaerythritolhexa(meth)acrylate, tri(2-acryloyloxyethyl)phosphate, tetramethylolmethane tri(meth)acrylate, tetramethylol propane tetra(meth)acrylate,derivatives thereof and the like.

One kind of the (meth)acrylic ester may be used alone, and two or morekinds thereof may be used in combination. The above-described(meth)acryl polymer may be a homopolymer of the above-described(meth)acrylic ester, or may be a copolymer of a polymerizable componentcontaining the above-described (meth)acrylic ester.

Concrete examples of the photoreaction initiator include2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one,2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone,2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide,bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide,bis(η5-2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)-phenyl)titanium,2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one,2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone,diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one,benzyldimethylketal,4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone,1-hydroxycyclohexylphenylketone,2-methyl-2-morpholino(4-thiomethylphenyl)propan-1-one,2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone,2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone oligomer,benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropylether, benzoin isobutyl ether, benzophenone, methyl o-benzoylbenzoate,4-phenylbenzophenone, 4-benzoyl-4′-methyl-diphenylsulfide,3,3′,4,4′-tetra(t-butylperoxycarbonyl)benzophenone,2,4,6-trimethylbenzophenone,4-benzoyl-N,N-dimethyl-N-[2-(1-oxo-2-propenyloxy)ethyl]benzenemethanaminium bromide, (4-benzoylbenzyl)trimethylammonium chloride,2-isopropylthioxanthone, 4-isopropylthioxanthone,2,4-diethylthioxanthone, 2,4-dichlorothioxanthone,1-chloro-4-propoxythioxanthone,2-(3-dimethylamino-2-hydroxy)-3,4-dimethyl-9H-thioxanthon-9-onemethochloride, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide,bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide,bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, triphenylmethyliumtetrakis(pentafluorophenyl) borate and the like. Only one kind of thephotoreaction initiator may be used, and two or more kinds thereof maybe used in combination.

Examples of the auxiliary include triethanolamine, triisopropanolamine,4,4′-dimethylaminobenzophenone (Michler's ketone),4,4′-diethylaminobenzophenone, 2-dimethylaminoethyl benzoic acid, andethyl 4-dimethylaminobenzoate. Also, (n-butoxy)ethyl4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 2-ethylhexyl4-dimethylaminobenzoate, 2,4-diethylthioxanthone,2,4-diisopropylthioxanthone and the like can be recited. One kind of theauxiliary may be used alone and two or more kinds thereof may be used incombination.

It is preferred that the auxiliary be benzyldimethylketal,1-hydroxycyclohexylphenyl ketone, benzoylisopropyl ether,4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl) ketone,2-hydroxy-2-methyl-1-phenylpropan-1-one, or triphenylmethyliumtetrakis(pentafluorophenyl) borate.

In 100% by weight of the polymerizable composition, the content of thephotoreaction initiator is preferably 0.01% by weight or more, morepreferably 0.1% by weight or more and is preferably 10% by weight orless, more preferably 5% by weight or less. When the content of thephotoreaction initiator is in the range from the above-described lowerlimit to the above-described upper limit, the photocurability and thestorage stability further increase.

It is preferred that the polyvinyl acetate be a polymer of apolymerizable composition containing vinyl acetate and a monomer havingthe above-described functional group because excellent effect of thepresent invention is achieved.

Examples of the monomer having the above-described functional groupinclude 3-methyl-3-butyl 1-ol, ethylene glycol monovinyl ether,isopropylacrylamide and the like.

From the viewpoint of effectively enhancing the sound insulatingproperties, the weight average molecular weight of the polyvinyl acetateis preferably 250000 or more, more preferably 300000 or more, furtherpreferably 400000 or more, especially preferably 500000 or more. Fromthe viewpoint of enhancing the interlayer adhesion, the weight averagemolecular weight of the polyvinyl acetate is preferably 1200000 or less,more preferably 900000 or less.

The weight average molecular weight refers to a weight average molecularweight, calculated on the polystyrene equivalent basis, measured by gelpermeation chromatography (GPC).

The method for polymerizing the polymerizable composition to synthesizethe polyvinyl acetate is not particularly limited. Examples of thesynthesizing method include a solution polymerization, suspensionpolymerization, UV polymerization and the like.

From the viewpoint of increasing the transparency of the interlayerfilm, and effectively enhancing the sound insulating properties and theinterlayer adhesion in the interlayer film having increasedtransparency, the synthesizing method of the polyvinyl acetate ispreferably solution polymerization.

For example, the polyvinyl acetal resin can be obtained by acetalizingpolyvinyl alcohol (PVA) with an aldehyde. It is preferred that thepolyvinyl acetal resin be an acetalized product of polyvinyl alcohol.The polyvinyl alcohol can be obtained, for example, by saponifyingpolyvinyl acetate. The saponification degree of the polyvinyl alcoholgenerally falls within the range of 70 to 99.9% by mole.

The average polymerization degree of the polyvinyl alcohol (PVA) ispreferably 200 or more, more preferably 500 or more, even morepreferably 1500 or more, further preferably 1600 or more, especiallypreferably 2600 or more, most preferably 2700 or more and is preferably5000 or less, more preferably 4000 or less, further preferably 3500 orless. When the average polymerization degree is the above-describedlower limit or more, the penetration resistance of laminated glass isfurther enhanced. When the average polymerization degree is theabove-described upper limit or less, formation of an interlayer film isfacilitated.

The average polymerization degree of the polyvinyl alcohol is determinedby a method in accordance with JIS K6726 “Testing methods for polyvinylalcohol”.

It is preferred that the number of carbon atoms of the acetal group inthe polyvinyl acetal resin lie within the range of 3 to 5, and it ispreferred that the number of carbon atoms of the acetal group be 4 or 5.

In general, as the aldehyde, an aldehyde with 1 to 10 carbon atoms issuitably used. Examples of the aldehyde with 1 to 10 carbon atomsinclude formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde,isobutyraldehyde, n-valeraldehyde, 2-ethylbutyraldehyde,n-hexylaldehyde, n-octylaldehyde, n-nonylaldehyde, n-decylaldehyde,benzaldehyde, and the like. Acetaldehyde, propionaldehyde,n-butyraldehyde, isobutyraldehyde, n-hexylaldehyde or n-valeraldehyde ispreferred, acetaldehyde, propionaldehyde, n-butyraldehyde,isobutyraldehyde or n-valeraldehyde is more preferred, andn-butyraldehyde or n-valeraldehyde is further preferred. One kind of thealdehyde may be used alone, and two or more kinds thereof may be used incombination.

The content of the hydroxyl group (hydroxyl group amount) of thepolyvinyl acetal resin (1) is preferably 17% by mole or more, morepreferably 20% by mole or more, further preferably 22% by mole or more.The content of the hydroxyl group (the amount of hydroxyl groups) of thepolyvinyl acetal resin (1) is preferably 30% by mole or less, morepreferably 28% by mole or less, still more preferably 27% by mole orless, further preferably 25% by mole or less, especially preferably lessthan 25% by mole, most preferably 24% by mole or less. When the contentof the hydroxyl group is the above lower limit or more, the mechanicalstrength of the interlayer film is further enhanced. In particular, whenthe content of the hydroxyl group of the polyvinyl acetal resin (1) is20% by mole or more, the resin is high in reaction efficiency and isexcellent in productivity, when being 30% by mole or less, the soundinsulating properties of laminated glass are further enhanced, and whenbeing 28% by mole or less, the sound insulating properties are furtherenhanced. Moreover, when the content of the hydroxyl group is theabove-described upper limit or less, the flexibility of the interlayerfilm is enhanced and the handling of the interlayer film is facilitated.

The content of the hydroxyl group of each of the polyvinyl acetal resin(2) and the polyvinyl acetal resin (3) is preferably 25% by mole ormore, more preferably 28% by mole or more, still more preferably 30% bymole or more, further preferably more than 31% by mole. Each of thecontents of the hydroxyl group of the polyvinyl acetal resin (2) and thepolyvinyl acetal resin (3) is further preferably 31.5% by mole or more,further preferably 32% by mole or more, especially preferably 33% bymole or more. Each of the contents of the hydroxyl group of thepolyvinyl acetal resin (2) and the polyvinyl acetal resin (3) ispreferably 37% by mole or less, more preferably 36.5% by mole or less,further preferably 36% by mole or less. When the content of the hydroxylgroup is the above-described lower limit or more, the adhesive force ofthe interlayer film is further enhanced. Moreover, when the content ofthe hydroxyl group is the above-described upper limit or less, theflexibility of the interlayer film is enhanced and the handling of theinterlayer film is facilitated.

From the viewpoint of further enhancing the sound insulating properties,it is preferred that the content of the hydroxyl group of the polyvinylacetal resin (1) be lower than the content of the hydroxyl group of thepolyvinyl acetal resin (2). From the viewpoint of further enhancing thesound insulating properties, it is preferred that the content of thehydroxyl group of the polyvinyl acetal resin (1) be lower than thecontent of the hydroxyl group of the polyvinyl acetal resin (3). Fromthe viewpoint of still further enhancing the sound insulatingproperties, the absolute value of a difference between the content ofthe hydroxyl group of the polyvinyl acetal resin (1) and the content ofthe hydroxyl group of the polyvinyl acetal resin (2) is preferably 1% bymole or more, more preferably 5% by mole or more, further preferably 9%by mole or more, especially preferably 10% by mole or more, mostpreferably 12% by mole or more. From the viewpoint of still furtherenhancing the sound insulating properties, the absolute value of adifference between the content of the hydroxyl group of the polyvinylacetal resin (1) and the content of the hydroxyl group of the polyvinylacetal resin (3) is preferably 1% by mole or more, more preferably 5% bymole or more, further preferably 9% by mole or more, especiallypreferably 10% by mole or more, most preferably 12% by mole or more. Anabsolute value of difference between the content of the hydroxyl groupof the polyvinyl acetal resin (1) and the content of the hydroxyl groupof the polyvinyl acetal resin (2) is preferably 20% by mole or less. Anabsolute value of difference between the content of the hydroxyl groupof the polyvinyl acetal resin (1) and the content of the hydroxyl groupof the polyvinyl acetal resin (3) is preferably 20% by mole or less.

The content of the hydroxyl group of the polyvinyl acetal resin is amole fraction, represented in percentage, obtained by dividing theamount of ethylene groups to which the hydroxyl group is bonded by thetotal amount of ethylene groups in the main chain. For example, theamount of ethylene groups to which the hydroxyl group is bonded can bemeasured in accordance with JIS K6728 “Testing methods for polyvinylbutyral”.

The acetylation degree (the amount of acetyl groups) of the polyvinylacetal resin (1) is preferably 0.01% by mole or more, more preferably0.1% by mole or more, even more preferably 7% by mole or more, furtherpreferably 9% by mole or more and is preferably 30% by mole or less,more preferably 25% by mole or less, further preferably 24% by mole orless, especially preferably 20% by mole or less. When the acetylationdegree is the above-described lower limit or more, the compatibilitybetween the polyvinyl acetal resin and a plasticizer is enhanced. Whenthe acetylation degree is the above-described upper limit or less, withregard to the interlayer film and laminated glass, the moistureresistance thereof is enhanced. In particular, when the acetylationdegree of the polyvinyl acetal resin (1) is 0.1% by mole or more and is25% by mole or less, the resulting laminated glass is more excellent inpenetration resistance.

The acetylation degree of each of the polyvinyl acetal resin (2) and thepolyvinyl acetal resin (3) is preferably 0.01% by mole or more, morepreferably 0.5% by mole or more and is preferably 10% by mole or less,more preferably 2% by mole or less. When the acetylation degree is theabove-described lower limit or more, the compatibility between thepolyvinyl acetal resin and a plasticizer is enhanced. When theacetylation degree is the above-described upper limit or less, withregard to the interlayer film and laminated glass, the moistureresistance thereof is enhanced.

The acetylation degree is a mole fraction, represented in percentage,obtained by dividing the amount of ethylene groups to which the acetylgroup is bonded by the total amount of ethylene groups in the mainchain. For example, the amount of ethylene groups to which the acetylgroup is bonded can be measured in accordance with JIS K6728 “Testingmethods for polyvinyl butyral”.

The acetalization degree of the polyvinyl acetal resin (1) (thebutyralization degree in the case of a polyvinyl butyral resin) ispreferably 47% by mole or more, more preferably 60% by mole or more andis preferably 85% by mole or less, more preferably 80% by mole or less,further preferably 75% by mole or less. When the acetalization degree isthe above-described lower limit or more, the compatibility between thepolyvinyl acetal resin and a plasticizer is enhanced. When theacetalization degree is the above-described upper limit or less, thereaction time required for producing the polyvinyl acetal resin isshortened.

The acetalization degree of each of the polyvinyl acetal resin (2) andthe polyvinyl acetal resin (3) (the butyralization degree in the case ofa polyvinyl butyral resin) is preferably 55% by mole or more, morepreferably 60% by mole or more and is preferably 75% by mole or less,more preferably 71% by mole or less. When the acetalization degree isthe above-described lower limit or more, the compatibility between thepolyvinyl acetal resin and a plasticizer is enhanced. When theacetalization degree is the above-described upper limit or less, thereaction time required for producing the polyvinyl acetal resin isshortened.

The acetalization degree is determined in the following manner. From thetotal amount of the ethylene group in the main chain, the amount of theethylene group to which the hydroxyl group is bounded and the amount ofthe ethylene group to which the acetyl group is bonded are subtracted.The obtained value is divided by the total amount of the ethylene groupin the main chain to obtain a mole fraction. The mole fractionrepresented in percentage is the acetalization degree.

In this connection, it is preferred that the content of the hydroxylgroup (the amount of hydroxyl groups), the acetalization degree (thebutyralization degree) and the acetylation degree be calculated from theresults measured by a method in accordance with JIS K6728 “Testingmethods for polyvinyl butyral”. In this context, a method in accordancewith ASTM D1396-92 may be used. When the polyvinyl acetal resin is apolyvinyl butyral resin, the content of the hydroxyl group (the amountof hydroxyl groups), the acetalization degree (the butyralizationdegree) and the acetylation degree can be calculated from the resultsmeasured by a method in accordance with JIS K6728 “Testing methods forpolyvinyl butyral”.

The polyester resin can be produced by a commonly known method forproducing polyester. The polyester resin can be produced, for example,by a method of obtaining polyester by condensation reaction between apolybasic acid and a polyhydric alcohol, a method of obtaining polyesterby transesterification between an alkyl ester of polybasic acid and apolyhydric alcohol, or a method of obtaining polyester by furtherpolymerizing the polyester obtained by the above-described method in thepresence of a polymerization catalyst.

Examples of the polybasic acid include aromatic dicarboxylic acids suchas terephthalic acid, isophthalic acid, orthophthalic acid, andnaphthalene dicarboxylic acid; aliphatic dicarboxylic acids such assuccinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid,dodecanedioic acid, and dimer acid; unsaturated dicarboxylic acids suchas (anhydrous) maleic acid, fumaric acid, dodecenylsuccinic anhydride,and terpene-maleic acid adduct; alicyclic dicarboxylic acids such as1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic acid,hexahydroisophthalic acid, and 1,2-cyclohexenedicarboxylic acid; tri- orhigher valent carboxylic acids such as (anhydrous) trimellitic acid,(anhydrous) pyromellitic acid, and methylcyclohexene tricarboxylic acid;monocarboxylic acids such as 4,4-bis(4′-hydroxyphenyl)-pentanoic acid,4-mono(4′-hydroxyphenyl-pentanoic acid, and p-hydroxybenzoic acid, andthe like.

Examples of the polyhydric alcohols include aliphatic glycols such asethylene glycol, propylene glycol (1,2-propanediol), 1,3-propanediol,1,4-butanediol, 1,2-butanediol, 1,3-butanediol,2-methyl-1,3-propanediol, neopentyl glycol, 1,5-pentanediol,1,6-hexanediol, 3-methyl-1,5-pentanediol,2-ethyl-2-butyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol,1-methyl-1,8-octanediol, 3-methyl-1,6-hexanediol,4-methyl-1,7-heptanediol, 4-methyl-1,8-octanediol,4-propyl-1,8-octanediol, and 1,9-nonanediol; ether glycols such asdiethylene glycol, triethylene glycol, polyethylene glycol,polypropylene glycol, and polytetramethylene glycol; alicyclicpolyalcohols such as 1,4-cyclohexane dimethanol, 1,3-cyclohexanedimethanol, 1,2-cyclohexane dimethanol, tricyclodecane glycol, andhydrated bisphenol; tri- or more valent polyalcohols such astrimethylolpropane, trimethylolethane, and pentaerythritol, and thelike.

As a commercially available product of the above-described polyesterresin, for example, “elitel UE-3220” available from UNITIKA LTD. and“elitel UE-3223” available from UNITIKA LTD. can be recited.

(Plasticizer)

It is preferred that the first layer contain a plasticizer (hereinafter,sometimes described as a plasticizer (1)). It is preferred that thesecond layer contain a plasticizer (hereinafter, sometimes described asa plasticizer (2)). It is preferred that the third layer contain aplasticizer (hereinafter, sometimes described as a plasticizer (3)). Bythe use of the plasticizer, and further by using a polyvinyl acetalresin and a plasticizer together, the adhesive force of a layercontaining the polyvinyl acetal resin and the plasticizer to alamination glass member or another layer is moderately enhanced. Theplasticizer is not particularly limited. The plasticizer (1), theplasticizer (2) and the plasticizer (3) may be the same as or differentfrom one another. One kind of each of the plasticizer (1), theplasticizer (2) and the plasticizer (3) may be used alone, and two ormore kinds thereof may be used in combination.

Examples of the plasticizer include organic ester plasticizers such as amonobasic organic acid ester and a polybasic organic acid ester, organicphosphate plasticizers such as an organic phosphate plasticizer and anorganic phosphite plasticizer, and the like. Organic ester plasticizersare preferred. It is preferred that the plasticizer be a liquidplasticizer.

Examples of the monobasic organic acid ester include a glycol esterobtained by the reaction of a glycol with a monobasic organic acid, andthe like. Examples of the glycol include triethylene glycol,tetraethylene glycol, tripropylene glycol, and the like. Examples of themonobasic organic acid include butyric acid, isobutyric acid, caproicacid, 2-ethylbutyric acid, heptanoic acid, n-octylic acid,2-ethylhexanoic acid, n-nonylic acid, and decylic acid, and benzoic acidand the like.

Examples of the polybasic organic acid ester include ester compounds ofa polybasic organic acid and an alcohol having a linear or branchedstructure of 4 to 8 carbon atoms and the like. Examples of the polybasicorganic acid include phthalic acid, adipic acid, sebacic acid, azelaicacid, and the like.

Examples of the organic ester plasticizer include triethylene glycoldi-2-ethylpropanoate, triethylene glycol di-2-ethylbutyrate, triethyleneglycol di-2-ethylhexanoate, triethylene glycol dicaprylate, triethyleneglycol di-n-octanoate, triethylene glycol di-n-heptanoate, tetraethyleneglycol di-n-heptanoate, dibutyl sebacate, dioctyl azelate, dibutylcarbitol adipate, ethylene glycol di-2-ethylbutyrate, 1,3-propyleneglycol di-2-ethylbutyrate, 1,4-butylene glycol di-2-ethylbutyrate,diethylene glycol di-2-ethylbutyrate, diethylene glycoldi-2-ethylhexanoate, dipropylene glycol di-2-ethylbutyrate, triethyleneglycol di-2-ethylpentanoate, tetraethylene glycol di-2-ethylbutyrate,diethylene glycol dicaprylate, diethylene glycol dibenzoate, dipropyleneglycol dibenzoate, dibutyl maleate, bis(2-butoxyethyl) adipate, dibutyladipate, diisobutyl adipate, 2,2-butoxyethoxyethyl adipate, benzoic acidglycol ester, adipic acid 1,3-butyleneglycol polyester, dihexyl adipate,dioctyl adipate, hexyl cyclohexyl adipate, a mixture of heptyl adipateand nonyl adipate, diisononyl adipate, diisodecyl adipate, heptyl nonyladipate, tributyl citrate, tributyl acetylcitrate, diethyl carbonate,dibutyl sebacate, oil-modified sebacic alkyds, a mixture of a phosphoricacid ester and an adipic acid ester, and the like. Organic esterplasticizers other than these may be used. Other adipic acid estersother than the above-described adipic acid esters may be used.

Examples of the organic phosphate plasticizer include tributoxyethylphosphate, isodecyl phenyl phosphate, tricresyl phosphate, triisopropylphosphate, and the like.

It is preferred that the plasticizer be a diester plasticizerrepresented by the following formula (11).

In the foregoing formula (11), R1 and R2 each represent an organic groupwith 2 to 10 carbon atoms, R3 represents an ethylene group, anisopropylene group or a n-propylene group, and p represents an integerof 3 to 10. It is preferred that R1 and R2 in the foregoing formula (11)each be an organic group with 5 to 10 carbon atoms, and it is morepreferred that R1 and R2 each be an organic group with 6 to 10 carbonatoms.

It is preferred that the plasticizer include triethylene glycoldi-2-ethylhexanoate (3GO), triethylene glycol di-2-ethylbutyrate (3GH)or triethylene glycol di-2-ethylpropanoate. It is more preferred thatthe plasticizer include triethylene glycol di-2-ethylhexanoate ortriethylene glycol di-2-ethylbutyrate, and it is further preferred thatthe plasticizer include triethylene glycol di-2-ethylhexanoate.

In the first layer, the content of the plasticizer (1) relative to 100parts by weight of the resin (1) is referred to as content (1). When theresin (1) is the thermoplastic resin (1), 100 parts by weight of theresin (1) is 100 parts by weight of the thermoplastic resin (1). Whenthe resin (1) is the polyvinyl acetal resin (1), 100 parts by weight ofthe resin (1) is 100 parts by weight of the polyvinyl acetal resin (1).When the resin (1) is the polyester resin (1), 100 parts by weight ofthe resin (1) is 100 parts by weight of the polyester resin (1). Thesame basis applies to other resins. The content (1) is preferably 50parts by weight or more, more preferably 55 parts by weight or more,further preferably 60 parts by weight or more, and is preferably 130parts by weight or less, more preferably 100 parts by weight or less,further preferably 90 parts by weight or less, especially preferably 85parts by weight or less, most preferably 80 parts by weight or less.When the content (1) is the above-described lower limit or more, theflexibility of the interlayer film is enhanced and the handling of theinterlayer film is facilitated. When the content (1) is the above upperlimit or less, the penetration resistance of laminated glass is furtherenhanced.

In the second layer, the content of the plasticizer (2) relative to 100parts by weight of the thermoplastic resin (2) is referred to as content(2). When the thermoplastic resin (2) is the polyvinyl acetal resin (2)in the third layer, 100 parts by weight of the thermoplastic resin (2)is 100 parts by weight of the polyvinyl acetal resin (2). When thethermoplastic resin (2) is the polyester resin (2), 100 parts by weightof the thermoplastic resin (2) is 100 parts by weight of the polyesterresin (2). The same basis applies to other resins. In the third layer,the content of the plasticizer (3) relative to 100 parts by weight ofthe thermoplastic resin (3) is referred to as content (3). When thethermoplastic resin (3) is the polyvinyl acetal resin (3), 100 parts byweight of the thermoplastic resin (3) is 100 parts by weight of thepolyvinyl acetal resin (3). When the thermoplastic resin (3) is thepolyester resin (3), 100 parts by weight of the thermoplastic resin (3)is 100 parts by weight of the polyester resin (3). The same basisapplies to other resins. Each of the content (2) and the content (3) ispreferably 10 parts by weight or more, more preferably 15 parts byweight or more, and is preferably 40 parts by weight or less, morepreferably 39 parts by weight or less, further preferably 35 parts byweight or less, further preferably 32 parts by weight or less,especially preferably 30 parts by weight or less. When the content (2)and the content (3) are the above lower limit or more, the flexibilityof the interlayer film is enhanced and the handling of the interlayerfilm is facilitated. When the content (2) and the content (3) are theabove upper limit or less, the penetration resistance is furtherenhanced.

For the purpose of further enhancing the sound insulating properties oflaminated glass, it is preferred that the content (1) be larger than thecontent (2) and it is preferred that the content (1) be larger than thecontent (3).

From the viewpoint of further enhancing the sound insulating propertiesof laminated glass, each of the absolute value of difference between thecontent (2) and the content (1) and the absolute value of differencebetween the content (3) and the content (1) is preferably 10 parts byweight or more, more preferably 15 parts by weight or more, furtherpreferably 20 parts by weight or more. Each of the absolute value ofdifference between the content (2) and the content (1) and the absolutevalue of difference between the content (3) and the content (1) ispreferably 80 parts by weight or less, more preferably 75 parts byweight or less, further preferably 70 parts by weight or less.

(Compound having softening point of 70° C. or more and 200° C. or less)From the viewpoint of effectively enhancing the sound insulatingproperties, it is preferred that the first layer contain a compoundhaving a softening point of 70° C. or more and 200° C. or less(hereinafter, sometimes described as compound (A)). It is consideredthat by using the compound (A), the molecular motion increase in thevicinity of the glass transition temperature in the first layer, so thatthe sound insulating properties are enhanced. One kind of the compound(A) may be used alone, and two or more kinds thereof may be used incombination.

From the viewpoint of effectively enhancing the sound insulatingproperties, the softening point of the compound (A) is preferably 80° C.or more, and is preferably 190° C. or less.

When the compound (A) is a compound not having a softening point, it ispreferred that the first layer contain a compound having a melting pointof 70° C. or more and 200° C. or less from the viewpoint of effectivelyenhancing the sound insulating properties.

It is preferred that the compound (A) be a compound that is differentfrom the thermoplastic resin. It is preferred that the compound (A) be acompound that is different from the polyvinyl acetal resin.

Concrete examples of the compound (A) include ester compounds having aplurality of aromatic rings; ether compounds having a plurality ofaromatic rings; tackifiers such as a rosin resin, a terpene resin and apetroleum resin; chlorinated paraffin, and the like.

As a commercially available product of the compound (A), KE-311(available from Arakawa Chemical Industries, Ltd., having a softeningpoint of 95° C.), EMPARA 70 (available from Ajinomoto Fine-Techno Co.,Inc., having a softening point of 100° C.) and the like can be recited.

In 100% by weight of the first layer, the content of the compound (A) ispreferably 20% by weight or more, more preferably 30% by weight or moreand is preferably 50% by weight or less, more preferably 40% by weightor less. The content of the compound (A) relative to 100 parts by weightof the thermoplastic resin (1) (100 parts by weight of the polyvinylacetal resin (1) when the thermoplastic resin (1) is the polyvinylacetal resin (1)) is preferably 50 parts by weight or more, morepreferably 60 parts by weight or more. The content of the compound (A)relative to 100 parts by weight of the thermoplastic resin (1) (100parts by weight of the polyvinyl acetal resin (1) when the thermoplasticresin (1) is the polyvinyl acetal resin (1)) is preferably 200 parts byweight or less, more preferably 150 parts by weight or less. When thecontent of the compound (A) is the above-described lower limit or more,the sound insulating properties are effectively enhanced. When thecontent of the compound (A) is the above-described upper limit or less,the formability is further improved.

(Heat Shielding Substance)

The interlayer film may contain a heat shielding substance (heatshielding compound). The first layer may contain a heat shieldingsubstance. The second layer may contain a heat shielding substance. Thethird layer may contain a heat shielding substance. One kind of the heatshielding substance may be used alone, and two or more kinds thereof maybe used in combination.

Ingredient X:

The interlayer film may contain at least one kind of Ingredient X amonga phthalocyanine compound, a naphthalocyanine compound and ananthracyanine compound. The first layer may contain the Ingredient X.The second layer may contain the Ingredient X. The third layer maycontain the Ingredient X. The Ingredient X is a heat shieldingsubstance. One kind of the Ingredient X may be used alone, and two ormore kinds thereof may be used in combination.

The Ingredient X is not particularly limited. Examples of the IngredientX that can be used include a phthalocyanine compound, a naphthalocyaninecompound and an anthracyanine compound that are conventionally known.

With regard to the interlayer film and laminated glass, from theviewpoint of further enhancing the heat shielding properties thereof, itis preferred that the Ingredient X be at least one kind selected fromthe group consisting of phthalocyanine, a derivative of phthalocyanine,naphthalocyanine and a derivative of naphthalocyanine, and it is morepreferred that the Ingredient X be at least one kind amongphthalocyanine and a derivative of phthalocyanine.

From the viewpoints of effectively enhancing the heat shieldingproperties and maintaining the visible light transmittance at a higherlevel over a long period of time, it is preferred that the Ingredient Xcontain vanadium atoms or copper atoms. It is preferred that theIngredient X contain vanadium atoms and it is also preferred that theIngredient X contain copper atoms. It is more preferred that theIngredient X be at least one kind among phthalocyanine containingvanadium atoms or copper atoms and a derivative of phthalocyaninecontaining vanadium atoms or copper atoms. With regard to the interlayerfilm and laminated glass, from the viewpoint of still further enhancingthe heat shielding properties thereof, it is preferred that theIngredient X have a structural unit in which an oxygen atom is bonded toa vanadium atom.

In 100% by weight of a layer containing the Ingredient X (a first layer,a second layer, or a third layer), the content of the Ingredient X ispreferably 0.001% by weight or more, more preferably 0.005% by weight ormore, further preferably 0.01% by weight or more, especially preferably0.02% by weight or more. In 100% by weight of a layer containing theIngredient X (a first layer, a second layer, or a third layer), thecontent of the Ingredient X is preferably 0.2% by weight or less, morepreferably 0.1% by weight or less, further preferably 0.05% by weight orless, especially preferably 0.04% by weight or less. When the content ofthe Ingredient X is the above lower limit or more and the above upperlimit or less, the heat shielding properties are sufficiently enhancedand the visible light transmittance is sufficiently enhanced. Forexample, it is possible to make the visible light transmittance 70% ormore.

Heat Shielding Particles:

The interlayer film may contain heat shielding particles. The firstlayer may contain heat shielding particles. The second layer may containheat shielding particles. The third layer may contain heat shieldingparticles. The heat shielding particles are of a heat shieldingsubstance. By the use of heat shielding particles, infrared rays (heatrays) can be effectively cut off. One kind of the heat shieldingparticles may be used alone, and two or more kinds thereof may be usedin combination.

From the viewpoint of further enhancing the heat shielding properties oflaminated glass, it is more preferred that the heat shielding particlesbe metal oxide particles. It is preferred that the heat shieldingparticles be particles (metal oxide particles) formed of an oxide of ametal.

The energy amount of an infrared ray with a wavelength of 780 nm orlonger which is longer than that of visible light is small as comparedwith an ultraviolet ray. However, the thermal action of infrared rays islarge, and when infrared rays are absorbed into a substance, heat isreleased from the substance. Accordingly, infrared rays are generallycalled heat rays. By the use of the heat shielding particles, infraredrays (heat rays) can be effectively cut off. In this connection, theheat shielding particle means a particle capable of absorbing infraredrays.

Specific examples of the heat shielding particles include metal oxideparticles such as aluminum-doped tin oxide particles, indium-doped tinoxide particles, antimony-doped tin oxide particles (ATO particles),gallium-doped zinc oxide particles (GZO particles), indium-doped zincoxide particles (IZO particles), aluminum-doped zinc oxide particles(AZO particles), niobium-doped titanium oxide particles, sodium-dopedtungsten oxide particles, cesium-doped tungsten oxide particles,thallium-doped tungsten oxide particles, rubidium-doped tungsten oxideparticles, tin-doped indium oxide particles (ITO particles), tin-dopedzinc oxide particles and silicon-doped zinc oxide particles, lanthanumhexaboride (LaB₆) particles, and the like. Heat shielding particlesother than these may be used. Since the heat ray shielding function ishigh, preferred are metal oxide particles, more preferred are ATOparticles, GZO particles, IZO particles, ITO particles or tungsten oxideparticles, and especially preferred are ITO particles or tungsten oxideparticles. In particular, since the heat ray shielding function is highand the particles are readily available, preferred are tin-doped indiumoxide particles (ITO particles), and also preferred are tungsten oxideparticles.

With regard to the interlayer film and laminated glass, from theviewpoint of further enhancing the heat shielding properties thereof, itis preferred that the tungsten oxide particles be metal-doped tungstenoxide particles. Examples of the “tungsten oxide particles” includemetal-doped tungsten oxide particles. Specifically, examples of themetal-doped tungsten oxide particles include sodium-doped tungsten oxideparticles, cesium-doped tungsten oxide particles, thallium-dopedtungsten oxide particles, rubidium-doped tungsten oxide particles, andthe like.

With regard to the interlayer film and laminated glass, from theviewpoint of further enhancing the heat shielding properties thereof,cesium-doped tungsten oxide particles are especially preferred. Withregard to the interlayer film and laminated glass, from the viewpoint ofstill further enhancing the heat shielding properties thereof, it ispreferred that the cesium-doped tungsten oxide particles be tungstenoxide particles represented by the formula: Cs_(0.33)WO₃.

The average particle diameter of the heat shielding particles ispreferably 0.01 μm or more, more preferably 0.02 μm or more, and ispreferably 0.1 μm or less, more preferably 0.05 μm or less. When theaverage particle diameter is the above lower limit or more, the heat rayshielding properties are sufficiently enhanced. When the averageparticle diameter is the above upper limit or less, the dispersibilityof heat shielding particles is enhanced.

The “average particle diameter” refers to the volume average particlediameter. The average particle diameter can be measured using a particlesize distribution measuring apparatus (“UPA-EX150” available fromNIKKISO CO., LTD.) or the like.

In 100% by weight of a layer containing the heat shielding particles (afirst layer, a second layer, or a third layer), the content of the heatshielding particles is preferably 0.01% by weight or more, morepreferably 0.1% by weight or more, further preferably 1% by weight ormore, especially preferably 1.5% by weight or more. In 100% by weight ofa layer containing the heat shielding particles (a first layer, a secondlayer, or a third layer), the content of the heat shielding particles ispreferably 6% by weight or less, more preferably 5.5% by weight or less,further preferably 4% by weight or less, especially preferably 3.5% byweight or less, most preferably 3% by weight or less. When the contentof the heat shielding particles is the above lower limit or more and theabove upper limit or less, the heat shielding properties aresufficiently enhanced and the visible light transmittance issufficiently enhanced.

(Metal Salt)

The interlayer film may contain at least one kind of metal salt(hereinafter, sometimes described as Metal salt M) among an alkali metalsalt, an alkaline earth metal salt, and a Mg salt. The first layer maycontain the Metal salt M. It is preferred that the second layer containthe Metal salt M. The third layer may contain the Metal salt M. Thesurface layer may contain the Metal salt M. By the use of the Metal saltM, controlling the adhesivity between the interlayer film and alamination glass member or the adhesivity between respective layers inthe interlayer film is facilitated. One kind of the Metal salt M may beused alone, and two or more kinds thereof may be used in combination.

It is preferred that the Metal salt M contain at least one kind of metalselected from the group consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr andBa. It is preferred that the metal salt included in the interlayer filmcontain at least one kind of metal among K and Mg.

Moreover, it is more preferred that the Metal salt M be an alkali metalsalt of an organic acid with 2 to 16 carbon atoms, an alkaline earthmetal salt of an organic acid with 2 to 16 carbon atoms, and a Mg saltof an organic acid with 2 to 16 carbon atoms, and it is furtherpreferred that the Metal salt M be a magnesium carboxylate with 2 to 16carbon atoms or a potassium carboxylate with 2 to 16 carbon atoms.

Examples of the magnesium carboxylate with 2 to 16 carbon atoms and thepotassium carboxylate with 2 to 16 carbon atoms include magnesiumacetate, potassium acetate, magnesium propionate, potassium propionate,magnesium 2-ethylbutyrate, potassium 2-ethylbutanoate, magnesium2-ethylhexanoate, potassium 2-ethylhexanoate, and the like.

The total of the contents of Mg and K in a layer containing the Metalsalt M (a first layer, a second layer or a third layer) is preferably 5ppm or more, more preferably 10 ppm or more, further preferably 20 ppmor more, preferably 300 ppm or less, more preferably 250 ppm or less,further preferably 200 ppm or less. When the total of the contents of Mgand K is the above lower limit or more and the above upper limit orless, the adhesivity between the interlayer film and a lamination glassmember or the adhesivity between respective layers in the interlayerfilm can be further well controlled.

(Ultraviolet Ray Screening Agent)

The interlayer film may contain an ultraviolet ray screening agent. Thefirst layer may contain an ultraviolet ray screening agent. The secondlayer may contain an ultraviolet ray screening agent. The third layermay contain an ultraviolet ray screening agent. By the use of anultraviolet ray screening agent, even when the interlayer film and thelaminated glass are used for a long period of time, the visible lighttransmittance becomes further difficult to be lowered. One kind of theultraviolet ray screening agent may be used alone, and two or more kindsthereof may be used in combination.

Examples of the ultraviolet ray screening agent include an ultravioletray absorber. It is preferred that the ultraviolet ray screening agentbe an ultraviolet ray absorber.

Examples of the ultraviolet ray screening agent include an ultravioletray screening agent containing a metal atom, an ultraviolet rayscreening agent containing a metal oxide, an ultraviolet ray screeningagent having a benzotriazole structure, an ultraviolet ray screeningagent having a benzophenone structure, an ultraviolet ray screeningagent having a triazine structure, an ultraviolet ray screening agenthaving a malonic acid ester structure, an ultraviolet ray screeningagent having an oxanilide structure, an ultraviolet ray screening agenthaving a benzoate structure, and the like.

Examples of the ultraviolet ray screening agent containing a metal atominclude platinum particles, particles in which the surface of platinumparticles is coated with silica, palladium particles, particles in whichthe surface of palladium particles is coated with silica, and the like.It is preferred that the ultraviolet ray screening agent not be heatshielding particles.

The ultraviolet ray screening agent is preferably an ultraviolet rayscreening agent having a benzotriazole structure, an ultraviolet rayscreening agent having a benzophenone structure, an ultraviolet rayscreening agent having a triazine structure, or an ultraviolet rayscreening agent having a benzoate structure. The ultraviolet rayscreening agent is more preferably an ultraviolet ray screening agenthaving a benzotriazole structure or an ultraviolet ray screening agenthaving a benzophenone structure, and is further preferably anultraviolet ray screening agent having a benzotriazole structure.

Examples of the ultraviolet ray screening agent containing a metal oxideinclude zinc oxide, titanium oxide, cerium oxide, and the like.Furthermore, with regard to the ultraviolet ray screening agentcontaining a metal oxide, the surface thereof may be coated with anymaterial. Examples of the coating material for the surface of theultraviolet ray screening agent containing a metal oxide include aninsulating metal oxide, a hydrolysable organosilicon compound, asilicone compound, and the like.

Examples of the ultraviolet ray screening agent having a benzotriazolestructure include 2-(2′-hydroxy-5′-methylphenyl)benzotriazole (“TinuvinP” available from BASF Japan Ltd.),2-(2′-hydroxy-3′,5′-di-t-butylphenyl)benzotriazole (“Tinuvin 320”available from BASF Japan Ltd.),2-(2′-hydroxy-3′-t-butyl-5-methylphenyl)-5-chlorobenzotriazole (“Tinuvin326” available from BASF Japan Ltd.),2-(2′-hydroxy-3′,5′-di-amylphenyl)benzotriazole (“Tinuvin 328” availablefrom BASF Japan Ltd.), and the like. It is preferred that theultraviolet ray screening agent be an ultraviolet ray screening agenthaving a benzotriazole structure containing a halogen atom, and it ismore preferred that the ultraviolet ray screening agent be anultraviolet ray screening agent having a benzotriazole structurecontaining a chlorine atom, because those are excellent in ultravioletray absorbing performance.

Examples of the ultraviolet ray screening agent having a benzophenonestructure include octabenzone (“Chimassorb 81” available from BASF JapanLtd.) and the like.

Examples of the ultraviolet ray screening agent having a triazinestructure include “LA-F70” available from ADEKA CORPORATION,2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-[(hexyl)oxy]-phenol (“Tinuvin1577FF” available from BASF Japan Ltd.) and the like.

Examples of the ultraviolet ray screening agent having a malonic acidester structure include dimethyl 2-(p-methoxybenzylidene)malonate,tetraethyl-2,2-(1,4-phenylenedimethylidene)bismalonate,2-(p-methoxybenzylidene)-bis(1,2,2,6,6-pentamethyl-4-piperidinyl)malonateand the like.

Examples of a commercial product of the ultraviolet ray screening agenthaving a malonic acid ester structure include Hostavin B-CAP, HostavinPR-25 and Hostavin PR-31 (any of these is available from Clariant JapanK.K.).

Examples of the ultraviolet ray screening agent having an oxanilidestructure include oxalic diamides having a substituted aryl group or thelike on the nitrogen atom, such asN-(2-ethylphenyl)-N′-(2-ethoxy-5-t-butylphenyl)oxalic acid diamide,N-(2-ethylphenyl)-N′-(2-ethoxy-phenyl)oxalic acid diamide and2-ethyl-2′-ethoxy-oxanilide (“Sanduvor VSU” available from ClariantJapan K.K.).

Examples of the ultraviolet ray screening agent having a benzoatestructure include2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate (“Tinuvin120” available from BASF Japan Ltd.) and the like.

In 100% by weight of a layer containing the ultraviolet ray screeningagent (a first layer, a second layer, or a third layer), the content ofthe ultraviolet ray screening agent is preferably 0.1% by weight ormore, more preferably 0.2% by weight or more, further preferably 0.3% byweight or more, especially preferably 0.5% by weight or more. In 100% byweight of a layer containing the ultraviolet ray screening agent (afirst layer, a second layer, or a third layer), the content of theultraviolet ray screening agent is preferably 2.5% by weight or less,more preferably 2% by weight or less, further preferably 1% by weight orless, especially preferably 0.8% by weight or less. When the content ofthe ultraviolet ray screening agent is the above-described lower limitor more and the above-described upper limit or less, deterioration invisible light transmittance after a lapse of a period can be furthersuppressed. In particular, by setting the content of the ultraviolet rayscreening agent to be 0.2% by weight or more in 100% by weight of alayer containing the ultraviolet ray screening agent, with regard to theinterlayer film and laminated glass, the lowering in visible lighttransmittance thereof after the lapse of a certain period of time can besignificantly suppressed.

(Oxidation Inhibitor)

The interlayer film may contain an oxidation inhibitor. The first layermay contain an oxidation inhibitor. The second layer may contain anoxidation inhibitor. The third layer may contain an oxidation inhibitor.One kind of the oxidation inhibitor may be used alone, and two or morekinds thereof may be used in combination.

Examples of the oxidation inhibitor include a phenol-based oxidationinhibitor, a sulfur-based oxidation inhibitor, a phosphorus-basedoxidation inhibitor, and the like. The phenol-based oxidation inhibitoris an oxidation inhibitor having a phenol skeleton. The sulfur-basedoxidation inhibitor is an oxidation inhibitor containing a sulfur atom.The phosphorus-based oxidation inhibitor is an oxidation inhibitorcontaining a phosphorus atom.

It is preferred that the oxidation inhibitor be a phenol-based oxidationinhibitor or a phosphorus-based oxidation inhibitor.

Examples of the phenol-based oxidation inhibitor include2,6-di-t-butyl-p-cresol (BHT), butyl hydroxyanisole (BHA),2,6-di-t-butyl-4-ethylphenol, stearylR-(3,5-di-t-butyl-4-hydroxyphenyl)propionate,2,2′-methylenebis-(4-methyl-6-butylphenol),2,2′-methylenebis-(4-ethyl-6-t-butylphenol),4,4′-butylidene-bis-(3-methyl-6-t-butylphenol),1,1,3-tris-(2-methyl-hydroxy-5-t-butylphenyl)butane,tetrakis[methylene-3-(3′,5′-butyl-4-hydroxyphenyl)propionate]methane,1,3,3-tris-(2-methyl-4-hydroxy-5-t-butylphenol)butane,1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene,bis(3,3′-t-butylphenol)butyric acid glycol ester,bis(3-t-butyl-4-hydroxy-5-methylbenzenepropanoicacid)ethylenebis(oxyethylene), and the like. One kind or two or morekinds among these oxidation inhibitors are suitably used.

Examples of the phosphorus-based oxidation inhibitor include tridecylphosphite, tris(tridecyl) phosphite, triphenyl phosphite, trinonylphenylphosphite, bis(tridecyl)pentaerithritol diphosphite,bis(decyl)pentaerithritol diphosphite, tris(2,4-di-t-butylphenyl)phosphite, bis(2,4-di-t-butyl-6-methylphenyl)ethyl ester phosphorousacid, 2,2′-methylenebis(4,6-di-t-butyl-1-phenyloxy)(2-ethylhexyloxy)phosphorus, and the like. One kind or two or more kindsamong these oxidation inhibitors are suitably used.

Examples of a commercial product of the oxidation inhibitor include“IRGANOX 245” available from BASF Japan Ltd., “IRGAFOS 168” availablefrom BASF Japan Ltd., “IRGAFOS 38” available from BASF Japan Ltd.,“Sumilizer BHT” available from Sumitomo Chemical Co., Ltd., “IRGANOX1010” available from BASF Japan Ltd., and the like.

With regard to the interlayer film and laminated glass, in order tomaintain high visible light transmittance thereof over a long period oftime, it is preferred that the content of the oxidation inhibitor be0.1% by weight or more in 100% by weight of the interlayer film or in100% by weight of the layer containing the oxidation inhibitor (a firstlayer, a second layer or a third layer). Moreover, since an effectcommensurate with the addition of an oxidation inhibitor is notattained, it is preferred that the content of the oxidation inhibitor be2% by weight or less in 100% by weight of the interlayer film or in 100%by weight of the layer containing the oxidation inhibitor.

(Other Ingredients)

Each of the first layer, the second layer and the third layer maycontain additives such as a coupling agent containing silicon, aluminumor titanium, a dispersing agent, a surfactant, a flame retardant, anantistatic agent, a pigment, a dye, a moisture-resistance improvingagent, a cross-linking agent, a fluorescent brightening agent and aninfrared ray absorber, as necessary. One kind of these additives may beused alone, and two or more kinds thereof may be used in combination.

(Other Details of Interlayer Film for Laminated Glass)

The distance between one end and the other end of the interlayer film ispreferably 0.5 m or more, more preferably 0.8 m or more, and especiallypreferably 1 m or more, and is preferably 3 m or less, more preferably 2m or less, and especially preferably 1.5 m or less. When the interlayerfilm has a longitudinal direction and a width direction, the distancebetween one end and the other end is a distance in the longitudinaldirection of the interlayer film. When the interlayer film has a squareplanar shape, the distance between one end and the other end is adistance between one end and the other end that are opposed to eachother.

The thickness of the interlayer film is not particularly limited. Fromthe viewpoint of the practical aspect and the viewpoint of sufficientlyenhancing the penetration resistance and the flexural rigidity oflaminated glass, the thickness of the interlayer film is preferably 0.1mm or more, more preferably 0.25 mm or more, and is preferably 3 mm orless, more preferably 2 mm or less, further preferably 1.5 mm or less.When the thickness of the interlayer film is the above lower limit ormore, the penetration resistance and the flexural rigidity of laminatedglass are enhanced. When the thickness of the interlayer film is theabove-described upper limit or less, the transparency of the interlayerfilm is further improved.

The thickness of the interlayer film is designated as T. The thicknessof the first layer is preferably 0.0625T or more, more preferably 0.1Tor more, and is preferably 0.4T or less, more preferably 0.375T or less,further preferably 0.25T or less, and further preferably 0.15T or less.When the thickness of the first layer is 0.4T or less, the flexuralrigidity is further improved.

The thickness of each of the second layer and the third layer ispreferably 0.3T or more, more preferably 0.3125T or more, furtherpreferably 0.375T or more and is preferably 0.9375T or less, morepreferably 0.9T or less. The thickness of each of the second layer andthe third layer may be 0.46875T or less, and may be 0.45T or less. Whenthe thickness of each of the second layer and the third layer is theabove-described lower limit or more and the above-described upper limitor less, the rigidity and the sound insulating properties of thelaminated glass are further enhanced.

The total thickness of the second layer and the third layer ispreferably 0.625T or more, more preferably 0.75T or more, furtherpreferably 0.85T or more and is preferably 0.9375T or less, morepreferably 0.9T or less. When the total thickness of the second layerand the third layer is the above-described lower limit or more and theabove-described upper limit or less, the rigidity and the soundinsulating properties of the laminated glass are further enhanced.

The interlayer film may be an interlayer film having a uniformthickness, or may be an interlayer film having varying thickness. Thesectional shape of the interlayer film may be a rectangular shape andmay be a wedge-like shape.

The production method of the interlayer film according to the presentinvention is not particularly limited. Examples of the production methodof the interlayer film according to the present invention include amethod of separately forming resin compositions used for constitutingrespective layers into respective layers, and then layering the obtainedlayers, a method of coextruding resin compositions used for constitutingrespective layers with an extruder and layering the layers, and thelike. A production method of extrusion-molding is preferred because themethod is suitable for continuous production.

For the reason of excellent production efficiency of the interlayerfilm, it is preferred that the second layer and the third layer containthe same polyvinyl acetal resin. For the reason of excellent productionefficiency of the interlayer film, it is preferred that the second layerand the third layer contain the same polyvinyl acetal resin and the sameplasticizer. For the reason of excellent production efficiency of theinterlayer film, it is further preferred that the second layer and thethird layer be formed of the same resin composition.

It is preferred that the interlayer film have protrusions and recesseson at least one surface of the surfaces of both sides. It is preferredthat the interlayer film have protrusions and recesses on surfaces ofboth sides. Examples of the method for forming the protrusions andrecesses include, but are not particularly limited to, a lip embossmethod, an emboss roll method, a calender roll method, and a profileextrusion method. The emboss roll method is preferred because a largenumber of embosses of the protrusions and recesses, which is aquantitatively constant protrusion and recess pattern, can be formed.

(Laminated Glass)

FIG. 3 is a sectional view schematically showing an example of laminatedglass prepared with the interlayer film for laminated glass shown inFIG. 1.

A laminated glass 31 shown in FIG. 3 is provided with a first laminationglass member 21, a second lamination glass member 22 and the interlayerfilm 11. The interlayer film 11 is arranged between the first laminationglass member 21 and the second lamination glass member 22 to besandwiched therebetween.

The first lamination glass member 21 is layered on a first surface 11 aof the interlayer film 11. The second lamination glass member 22 islayered on a second surface 11 b opposite to the first surface 11 a ofthe interlayer film 11. The first lamination glass member 21 is layeredon the outer surface 1 a of the first layer 1. The second laminationglass member 22 is layered on an outer surface 3 a of the third layer 3.

FIG. 4 is a sectional view schematically showing an example of laminatedglass prepared with the interlayer film for laminated glass shown inFIG. 2.

A laminated glass 31A shown in FIG. 4 is provided with the firstlamination glass member 21, the second lamination glass member 22 andthe interlayer film 11A. The interlayer film 11A is arranged between thefirst lamination glass member 21 and the second lamination glass member22 to be sandwiched therebetween.

The first lamination glass member 21 is layered on the first surface 11a of the interlayer film 11A. The second lamination glass member 22 islayered on the second surface 11 b opposite to the first surface 11 a ofthe interlayer film 11A.

As described above, the laminated glass is provided with a firstlamination glass member, a second lamination glass member and aninterlayer film, and the interlayer film is the interlayer film forlaminated glass according to the present invention. In the laminatedglass, the above-mentioned interlayer film is arranged between the firstlamination glass member and the second lamination glass member.

Examples of the lamination glass member include a glass plate, a PET(polyethylene terephthalate) film, and the like. As the laminated glass,laminated glass in which an interlayer film is sandwiched between aglass plate and a PET film or the like, as well as laminated glass inwhich an interlayer film is sandwiched between two glass plates, isincluded. The laminated glass is a laminate provided with a glass plate,and it is preferred that at least one glass plate be used. It ispreferred that each of the first lamination glass member and the secondlamination glass member be a glass plate or a PET film, and thelaminated glass be provided with a glass plate as at least one among thefirst lamination glass member and the second lamination glass member. Itis preferred that both of the first lamination glass member and thesecond lamination glass member be glass plates (a first glass plate anda second glass plate). The interlayer film is arranged between a firstglass plate and a second glass plate to suitably obtain laminated glass.

Examples of the glass plate include a sheet of inorganic glass and asheet of organic glass. Examples of the inorganic glass include floatplate glass, heat ray-absorbing plate glass, heat ray-reflecting plateglass, polished plate glass, figured glass, wired plate glass, and thelike. The organic glass is synthetic resin glass substituted forinorganic glass. Examples of the organic glass include a polycarbonateplate, a poly(meth)acrylic resin plate, and the like. Examples of thepoly(meth)acrylic resin plate include a polymethyl (meth)acrylate plate,and the like.

The thickness of the lamination glass member is preferably 1 mm or more,preferably 5 mm or less, more preferably 3 mm or less. Moreover, whenthe lamination glass member is a glass plate, the thickness of the glassplate is preferably 0.5 mm or more, more preferably 0.7 mm or more,preferably 5 mm or less, more preferably 3 mm or less. When thelamination glass member is a PET film, the thickness of the PET film ispreferably 0.03 mm or more and is preferably 0.5 mm or less.

The method for producing the laminated glass is not particularlylimited. First, the interlayer film is sandwiched between the firstlamination glass member and the second lamination glass member to obtaina laminate. Then, for example, by passing the obtained laminate throughpressure rolls or subjecting the obtained laminate to decompressionsuction in a rubber bag, the air remaining between the first and thesecond lamination glass members and the interlayer film is removed.Then, the laminate is preliminarily bonded together at about 70 to 110°C. to obtain a preliminarily press-bonded laminate. Next, by putting thepreliminarily press-bonded laminate into an autoclave or by pressing thelaminate, the laminate is press-bonded at about 120 to 150° C. and undera pressure of 1 to 1.5 MPa. In this way, laminated glass can beobtained. At the time of producing the laminated glass, a first layer, asecond layer and a third layer may be layered.

Each of the interlayer film and the laminated glass can be used forautomobiles, railway vehicles, aircraft, ships, buildings, and the like.Each of the interlayer film and the laminated glass can also be used forapplications other than these applications. It is preferred that theinterlayer film and the laminated glass be an interlayer film andlaminated glass for vehicles or for building respectively, and it ismore preferred that the interlayer film and the laminated glass be aninterlayer film and laminated glass for vehicles respectively. Each ofthe interlayer film and the laminated glass can be used for awindshield, side glass, rear glass, or roof glass of an automobile, andthe like. The interlayer film and the laminated glass are suitably usedfor automobiles. The interlayer film is used for obtaining laminatedglass of an automobile.

Hereinafter, the present invention will be described in more detail withreference to examples. The present invention is not limited only tothese examples.

The following materials were prepared.

(Resin) Polyvinyl Acetal Resin:

Polyvinyl acetal resins shown in the following Table 1 were used. In allpolyvinyl acetal resins used, n-butyraldehyde which has 4 carbon atomsis used for the acetalization. With regard to the polyvinyl acetalresin, the acetalization degree (the butyralization degree), theacetylation degree and the content of the hydroxyl group were measuredby a method in accordance with JIS K6728 “Testing methods for polyvinylbutyral”. In this connection, even in the cases of being measuredaccording to ASTM D1396-92, numerical values similar to those obtainedby a method in accordance with JIS K6728 “Testing methods for polyvinylbutyral” were exhibited.

Polyester Resin:

PEs1 (UE3220, available from UNITIKA LTD.)

PEs2 (UE3223, available from UNITIKA LTD.)

(Meth)acryl Polymer: Meth(acryl) Polymers Ac1, Ac2, Ac3, Ac4 and Ac5Obtained by the Following Synthesizing Method

A polymerizable composition having the blending composition shown in thefollowing Table 3 was sandwiched between two PET sheets treated to havea mold releasability on one side (available from NIPPA, having athickness of 50 μm) to form a polymerizable composition layer having athickness of 100 μm. A spacer was arranged around the two PET sheets.The polymerizable composition layer was irradiated with ultraviolet raysat a dose of 3000 mJ/cm² with a high pressure mercury UV lamp to curethe polymerizable composition by reaction, and thus meth(acryl) polymersAc1, Ac2, Ac3, Ac4 and Ac5 were obtained.

Polyvinyl Acetate: Polyvinyl Acetate PVAc1 Obtained by the FollowingSynthesizing Method

A glass polymerization vessel equipped with a reflux condenser, adropping funnel, a thermometer, and a nitrogen inlet was prepared. Thispolymerization vessel was charged with 100 parts by weight of vinylacetate monomer, 1.0 part by weight of 3-methyl-3-butyl-1-ol, and 3.8parts by weight of methanol, and heated and stirred, and the interior ofthe polymerization vessel was replaced by nitrogen. Then the innertemperature of the polymerization vessel was controlled to 60° C., and0.02 parts by weight of tert-butylperoxy neodecanate which is apolymerization initiator, 150 parts by weight of vinyl acetate monomer,and 1.5 parts by weight of 3-methyl-3-butyl-1-ol were dropped over 4hours, and polymerized for 2 hours after end of the dropping, and thus asolution containing polyvinyl acetate was obtained. The solution wasdried for 3 hours in an oven at 110° C. to obtain polyvinyl acetatePVAc1.

Polyvinyl Acetate PVAc2 Obtained by the Following Synthesizing Method

A glass polymerization vessel equipped with a reflux condenser, adropping funnel, a thermometer, and a nitrogen inlet was prepared. Thispolymerization vessel was charged with 250 parts by weight of vinylacetate monomer and 3.8 parts by weight of methanol, and heated andstirred, and the interior of the polymerization vessel was replaced bynitrogen. Then the inner temperature of the polymerization vessel wascontrolled to 60° C., and 0.06 parts by weight of tert-butylperoxyneodecanate which is a polymerization initiator was dropped over 2.5hours, and polymerized for 2 hours after end of the dropping, and thus asolution containing poly vinyl acetate was obtained. The solution wasdried for 3 hours in an oven at 110° C. to obtain polyvinyl acetatePVAc2.

(Plasticizer)

Triethylene glycol di-2-ethylhexanoate (3GO)

Benzoic acid-based plasticizer (PB-3A, available from DIC Corporation)(P1)

Di-(2-butoxyethyl)adipate (DBEA)

Bis(2-butoxyethyl) adipate (D931)

Dibutyl adipate (DBA)

(Compound (A))

Compound (A1) (KE-311, available from Arakawa Chemical Industries, Ltd.,having a softening point of 95° C.)

Compound (A2) (EMPARA 70, available from Ajinomoto Fine-Techno Co.,Inc., having a softening point of 100° C.)

(Ultraviolet Ray Screening Agent)

Tinuvin 326(2-(2′-hydroxy-3′-t-butyl-5-methylphenyl)-5-chlorobenzotriazole,“Tinuvin 326” available from BASF Japan Ltd.)

(Oxidation Inhibitor)

BHT (2,6-di-t-butyl-p-cresol)

(Metal Salt)

Mg mixture (50:50 (weight ratio) mixture of magnesium 2-ethylbutyrateand magnesium acetate)

Example 1 Preparation of Composition for Forming First Layer:

One hundred parts by weight of a polyvinyl acetal resin of a kind shownin the following Table 1, 75 parts by weight of a plasticizer (3GO), 100parts by weight of compound (A1) (KE-311), 0.2 parts by weight of anultraviolet ray screening agent (Tinuvin 326) and 0.2 parts by weight ofan oxidation inhibitor (BHT) were mixed to obtain a composition forforming a first layer.

Preparation of Composition for Forming Second Layer and Third Layer:

One hundred parts by weight of a polyvinyl acetal resin of a kind shownin the following Table 1, 35 parts by weight of a plasticizer (3GO), 0.2parts by weight of an ultraviolet ray screening agent (Tinuvin 326), 0.2parts by weight of an oxidation inhibitor (BHT) and a Mg mixture whichgives a metal element concentration (Mg concentration) in the interlayerfilm to be obtained of 70 ppm were mixed to obtain a composition forforming a second layer and a third layer.

Preparation of Interlayer Film:

By coextruding the composition for forming a first layer and thecomposition for forming a second layer and a third layer using acoextruder, an interlayer film (780 μm in thickness) having a layeredstructure with a stack of a second layer (340 μm in thickness)/a firstlayer (100 μm in thickness)/a third layer (340 μm in thickness) wasprepared.

Preparation of Laminated Glass A (for Measuring Sound InsulatingProperties):

The center part of the obtained interlayer film was cut into a size of6.5 cm long x 6.5 cm wide. Next, the interlayer film was sandwichedbetween two sheets of green glass conforming to JIS R3208 (6.5 cm long x6.5 cm wide x 2 mm thick) to obtain a laminate. The laminate was putinto a rubber bag and the inside thereof was degassed for 20 minutes ata degree of vacuum of 2.6 kPa, after which the laminate was transferredinto an oven while keeping the laminate degassed, and furthermore, heldin place at 90° C. for 30 minutes and pressed under vacuum to subjectthe laminate to preliminary press-bonding. The preliminarilypress-bonded laminate was subjected to press-bonding for 20 minutesunder conditions of 135° C. and a pressure of 1.2 MPa in an autoclave toobtain a sheet of laminated glass A.

Examples 2 to 13 and Comparative Examples 1 to 2

An interlayer film and laminated glass were obtained in the same manneras that in Example 1 except that the kinds of the thermoplastic resin,the plasticizer and the compound (A) to be blended and the blendingamounts thereof for the composition for forming a first layer and thecomposition for forming a second layer and a third layer were set tothose listed in the following Tables 1, 2. In Examples 2 to 13 andComparative Examples 1 to 2, the same kinds of the ultraviolet rayscreening agent and the oxidation inhibitor as those used in Example 1were blended in the same blending amount as that in Example 1 (0.2 partsby weight relative to 100 parts by weight of the polyvinyl acetalresin), and the Mg mixture of the same kind as that in Example 1 wasblended in the same blending amount as in Example 1 (the amount thatgives a metal element concentration (Mg concentration) of 70 ppm in theinterlayer film).

In Example 7, each of the compound (A1) and the compound (A2) was usedin 60 parts by weight relative to 100 parts by weight of thethermoplastic resin.

Example 14 Preparation of First Layer:

The (meth)acryl polymer Ac1 obtained in the above (layer containing acured product, having a thickness of 100 μm) was prepared.

Preparation of Second Layer and Third Layer: Preparation of Compositionfor Forming Second Layer and Third Layer:

The following ingredients were mixed, and kneaded sufficiently with amixing roll to obtain a composition for forming a second layer and athird layer.

Polyvinyl acetal resin (PVB) 100 parts by weight

Plasticizer (3GO) 40 parts by weight

Metal salt M (Mg mixture) in such an amount that Mg is 70 ppm in theobtained second layer and third layer

Ultraviolet ray screening agent (Tinuvin326) in an amount of 0.2% byweight in the obtained second layer and third layer

Oxidation inhibitor (BHT) in an amount of 0.2% by weight in the obtainedsecond layer and third layer

The composition for forming the second layer and the third layer wasextruded with an extruder to obtain a second layer and the third layer(each having a thickness of 380 μm).

Preparation of Interlayer Film:

The second layer and the third layer were layered outside the firstlayer. An interlayer film having a structure of the second layer/thefirst layer/the third layer was obtained by laminating with a rolllaminator (“GDRB316 A3” available from ACCO BRANDS JAPAN) at 100° C. anda speed setting 3.

Preparation of Laminated Glass:

Laminated glass was obtained in the same manner as that in Example 1except that the obtained interlayer film was used.

Examples 15 to 17 and Comparative Example 3

An interlayer film and laminated glass were obtained in the same manneras that in Example 14 except that the kinds and the amounts of theingredients were set to that shown in the following Table 4. In Examples15 to 17 and Comparative Example 3, the same kinds of the ultravioletray screening agent and the oxidation inhibitor as those used in Example1 were blended in the same blending amounts as those in Example 14(blending amounts in the second layer and in the third layer), and theMg mixture of the same kind as that in Example 14 was blended in thesame blending amount as that in Example 14 (blending amounts in thesecond layer and the third layer).

Example 18 Preparation of Composition for Forming First Layer:

The following ingredients were mixed, and kneaded sufficiently with amixing roll to obtain a composition for forming a first layer.

Polyvinyl acetate PVAc1 100 parts by weight

Plasticizer (D931) 70 parts by weight

Ultraviolet ray screening agent (Tinuvin326) in an amount of 0.2% byweight in the obtained first layer

Oxidation inhibitor (BHT) in an amount of 0.2% by weight in the obtainedfirst layer

Preparation of Composition for Forming Second Layer and Third Layer:

The following ingredients were mixed, and kneaded sufficiently with amixing roll to obtain a composition for forming a second layer and athird layer.

Polyvinyl acetal resin (PVB) 100 parts by weight

Plasticizer (D931) 30 parts by weight

Metal salt M (Mg mixture) in such an amount that Mg is 70 ppm in theobtained second layer and third layer

Ultraviolet ray screening agent (Tinuvin326) in an amount of 0.2% byweight in the obtained second layer and third layer Oxidation inhibitor(BHT) in an amount of 0.2% by weight in the obtained second layer andthird layer

Preparation of Interlayer Film:

By coextruding the obtained composition for forming a first layer andthe obtained composition for forming a second layer and a third layerusing a coextruder, an interlayer film having a structure of a secondlayer (370 μm in thickness)/a first layer (100 μm in thickness)/a thirdlayer (370 μm in thickness) was obtained.

Comparative Example 2

An interlayer film and laminated glass were obtained in the same manneras that in Example 18 except that the kinds and the amounts of theingredients were set to that shown in the following Table 4. InComparative Example 2, the same kinds of the ultraviolet ray screeningagent and the oxidation inhibitor as those used in Example 18 wereblended in the same blending amounts as those in Example 18 (blendingamounts in the second layer and in the third layer), and the Mg mixtureof the same kind as that in Example 18 was blended in the same blendingamount as that in Example 18 (blending amounts in the second layer andthe third layer).

(Evaluation) (1) Viscoelasticity Measurement

Viscoelasticity of the first layer was measured in the following manner.

A kneaded composition for forming a first layer was prepared. Thekneaded composition was press-molded with a press molder at 150° C. toobtain a resin film having a thickness of 0.35 mm. The obtained resinfilm was left to stand for 2 hours at 25° C. and a relative humidity of30%. After leaving to stand for 2 hours, viscoelasticity was measuredusing “ARES-G2” available from TA Instruments. As a jig, a parallelplate of 8 mm in diameter was used. Measurement was performed under thecondition in which the temperature was decreased from 30° C. to −50° C.at a temperature decreasing rate of 3° C./minute and under the conditionof a frequency of 1 Hz and a strain of 1%. In the measurement resultsobtained, the peak temperature of the loss tangent was defined as theglass transition temperature Tg (° C.).

The resin film may be prepared in the following manner. The obtainedinterlayer film is stored in an environment at room temperature 23±2°C., relative humidity 25±5% for 1 month. Then in an environment at roomtemperature 23° C.±2° C., the second layer and the third layer areremoved from the interlayer film by peeling off, to obtain the firstlayer. The obtained first layer is press molded at 150° C. so that thethickness is 0.35 mm (at 150° C. without pressurization for 10 minutes,at 150° C. under pressurization for 10 minutes) to prepare a resin film.

Glass transition temperature Tg (° C.) of the first layer (resin film),first storage modulus G′ of the first layer at Tg−10° C. (G′(Tg−10°C.)), and second storage modulus G′ (G′ (Tg+10° C.)) of the first layerat Tg+10° C. were evaluated, and loss tangent tan δ (tan δ(Tg)) of thefirst layer at Tg of the first layer was determined. Whether each of theformula (1) and the formula (2) was satisfied was evaluated, and whenthe formula was satisfied, it was judged as “∘”, and when the formulawas not satisfied, the formula was determined as “x”

(1A) Viscoelasticity Measurement

A plurality of first layers having a thickness of 100 μm were layered toobtain a resin film having a thickness of 500 μm. Viscoelasticitymeasurement was conducted in the same manner as the viscoelasticitymeasurement of the above (1) except that the resin film in theviscoelasticity measurement of the above (1) was changed to the obtainedresin film.

(2) Sound Insulating Properties

Sound insulating properties of the obtained laminated glass wereevaluated using a sound box placed in a quiet room. The sound box is abox of 10 cm long, 10 cm wide, and 10 cm high formed by assembling 10mm-thick wooden plate materials, and an opening of 7 cm long and 7 cmwide was provided on one face. A music player having a speaker wasplaced inside the sound box. Then laminated glass A prepared formeasurement of the sound insulating properties was placed in the openingpart, and the laminated glass A was fixed to the opening part by fillingup the gap between the periphery of the laminated glass A and theopening part with clay. In the music player, beep sounds were recordedin advance so that beep sounds having a frequency of 500 Hz to 8000 Hz(beep signal sounds) come out of the speaker every constant time.

An evaluator listened to the sound from the music player in front of thelaminated glass A disposed in the opening part of the sound box, andsensory-evaluated whether the beep signal sound leaking from the soundbox through the laminated glass A does not increase at a specificfrequency, and sound insulation is achieved uniformly from the lowerfrequency side to the higher frequency side.

When the evaluator could hear the beep signal sounds uniformlyregardless of the frequency, the determination was “∘”, and when theevaluator heard at a specific frequency, a beep signal sound that islarger than those at other frequencies, the determination was “x”.

The details and the results are shown in the following Tables 1 to 4. Inthis connection, in the following Tables 1 to 4, the description ofingredients to be blended other than the resins such as thethermoplastic resin, the plasticizer and the compound (A) was omitted.

TABLE 1 Example 1 Example 2 Example 3 Example 4 Example 5 CompositionPolyvinyl acetal Average polymerization 3000 3000 3000 3000 3000 forforming resin degree of PVA first layer Content of hydroxyl mol % 23.323.3 23.3 24.2 23.3 group Acetylation degree mol % 18.1 18.1 18.1 11.718.1 Acetalization degree mol % 58.6 58.6 58.6 64.1 58.6 Content partsby 100 100 100 100 100 weight Plasticizer Kind 3GO 3GO 3GO 3GO 3GOContent parts by 75 75 75 85 125 weight Compound (A) Kind A1 A2 A2 A2 A2Content parts by 100 50 100 100 125 weight Composition Polyvinyl acetalAverage polymerization 1700 1700 1700 1700 1700 for forming resin degreeof PVA second and Content of hydroxyl mol % 30.6 30.6 30.6 30.6 30.6third group layers Acetylation degree mol % 0.9 0.9 0.9 0.9 0.9Acetalization degree mol % 68.5 68.5 68.5 68.5 68.5 Content parts by 100100 100 100 100 weight Plasticizer Kind 3GO 3GO 3GO 3GO 3GO Contentparts by 35 35 35 39 35 weight Evaluation (1) Glass transition ° C. 6.62.1 9.9 8.5 −3.9 Viscoelasticity temperature Tg measurement Loss tangenttanδ (Tg) 2.45 1.84 2.29 1.81 1.75 Whether or not Formula ∘ ∘ ∘ ∘ ∘ (1)is satisfied First storage modulus MPa 7.71 7.44 15.5 18.1 4.10 G′ (Tg −10° C.) Second storage modulus MPa 0.135 0.212 0.217 0.230 0.121 G′(Tg + 10° C.) Whether or not Formula ∘ ∘ ∘ ∘ ∘ (2) is satisfied (2)Sound insulating properties ∘ ∘ ∘ ∘ ∘ Comparative Comparative Example 6Example 7 Example 1 Example 2 Composition Polyvinyl acetal Averagepolymerization 3000 3000 3000 3000 for forming resin degree of PVA firstlayer Content of hydroxyl mol % 23.3 23.3 23.3 24.2 group Acetylationdegree mol % 18.1 18.1 18.1 11.7 Acetalization degree mol % 58.6 58.658.6 64.1 Content parts by 100 100 100 100 weight Plasticizer Kind DBEA3GO 3GO 3GO Content parts by 100 120 60 60 weight Compound (A) Kind A2A1 · A2 — — Content parts by 125 60 · 60 — — weight CompositionPolyvinyl acetal Average polymerization 1700 1700 1700 1700 for formingresin degree of PVA second and Content of hydroxyl mol % 30.6 30.6 30.630.6 third group layers Acetylation degree mol % 0.9 0.9 0.9 0.9Acetalization degree mol % 68.5 68.5 68.5 68.5 Content parts by 100 100100 100 weight Plasticizer Kind DBEA 3GO 3GO 3GO Content parts by 35 3535 39 weight Evaluation (1) Glass transition ° C. −3.6 −0.9 −0.6 2.0Viscoelasticity temperature Tg measurement Loss tangent tanδ (Tg) 2.081.83 1.52 1.46 Whether or not Formula ∘ ∘ x x (1) is satisfied Firststorage modulus MPa 9.55 3.83 5.99 13.3 G′ (Tg − 10° C.) Second storagemodulus MPa 0.148 0.087 0.145 0.294 G′ (Tg + 10° C.) Whether or notFormula ∘ ∘ ∘ ∘ (2) is satisfied (2) Sound insulating properties ∘ ∘ x x

TABLE 2 Example Example Example Example Example 8 Example 9 10 11 12 13Composition for Resin Kind PEs1 PEs2 PEs2 PEs2 PEs2 PEs2 forming firstContent parts by 100 100 100 100 100 100 layer weight Plasticizer KindP1 P1 P1 P1 P1 3GO Content parts by 36.5 22.5 30 100 120 80 weightCompound (A) Kind — — A2 A2 A2 A2 Content parts by — — 100 100 100 100weight Composition for Resin Kind PVB PVB PVB PVB PVB PVB forming secondAverage polymerization 1700 1700 1700 1700 1700 1700 and third layersdegree of PVA Content of hydroxyl group mol % 30.6 30.6 30.6 30.6 30.630.6 Acetylation degree mol % 0.9 0.9 0.9 0.9 0.9 0.9 Acetalizationdegree mol % 68.5 68.5 68.5 68.5 68.5 68.5 Content parts by 100 100 100100 100 100 weight Plasticizer Kind P1 P1 P1 P1 P1 3GO Content parts by40 40 40 40 40 40 weight Evaluation (1) Tg ° C. −9.9 2.4 0.2 −2.9 −5.6−12.0 Viscoelasticity Loss tangent tanδ (Tg) 2.42 2.15 3.09 3.19 3.192.53 measurement Whether or not Formula (1) ∘ ∘ ∘ ∘ ∘ ∘ is satisfiedFirst storage modulus G′ (Tg − MPa 135 102 20.4 50.0 89.7 13.5 10° C.)Second storage modulus MPa 0.545 0.642 0.106 0.164 0.232 0.144 G′ (Tg +10° C.) Whether or not Formula (2) ∘ ∘ ∘ ∘ ∘ ∘ is satisfied (2) Soundinsulating properties ∘ ∘ ∘ ∘ ∘ ∘

TABLE 3 Ac1 Ac2 Ac3 Ac4 Ac5 Ingredients EA parts by 35 18 weight HEAparts by 10 15 weight BzA parts by 23 23 90.9 90.9 95.2 weight BA partsby 32 44 weight AMP-20GY parts by 9.1 9.1 4.8 weight IRGACURE parts by0.2 0.2 0.2 0.2 0.2 184 weight 3GO parts by 15 weight PB-3A parts by 25weight

The details of the components shown in Table 3 used in synthesis of(meth)acryl polymers Ac1, Ac2, Ac3, Ac4 and Ac5 are as follows.

EA: ethyl acrylate (available from NIPPON SHOKUBAI CO., LTD.)

HEA: 2-hydroxyethyl acrylate (available from OSAKA ORGANIC CHEMICALINDUSTRY LTD.)

BzA: benzyl acrylate (available from OSAKA ORGANIC CHEMICAL INDUSTRYLTD., Viscoat #160)

BA: butyl acrylate (available from NIPPON SHOKUBAI CO., LTD.)

AMP-20GY: phenoxypolyethyleneglycol acrylate (available fromShin-Nakamura Chemical Co., Ltd.)

3GO: triethylene glycol di-2-ethylhexanoate

IRGACURE 184: 2,2-dimethoxy-1,2-diphenylethan-1-one (available fromBASF)

TABLE 4 Compar- Compar- Example Example Example Example Example ativeative 14 15 16 17 18 Example 3 Example 4 Composition Resin Kind Ac1 Ac2Ac3 Ac4 PVAc1 Ac5 PVAc2 for forming Content parts by 100 100 100 100 100100 100 first layer weight Plasticizer Kind — — 3GO P1 D931 — DBAContent parts by — — 15 25 70 — 50 weight Composition Resin Kind PVB PVBPVB PVB PVB PVB PVB for forming Average polymerization 1700 1700 17001700 1700 1700 1700 second and degree of PVA third Content of hydroxylgroup mol % 30.6 30.6 30.6 30.6 30.6 30.6 30.6 layers Acetylation degreemol % 0.9 0.9 0.9 0.9 0.9 0.9 0.9 Acetalization degree mol % 68.5 68.568.5 68.5 68.5 68.5 68.5 Content parts by 100 100 100 100 100 100 100weight Plasticizer Kind 3GO 3GO 3GO 3GO D931 3GO DBA Content parts by 4040 40 40 30 40 34 weight Evaluation (1) Tg ° C. −7.7 −9.9 −3.6 −1.1 1.916.8 −2.0 Visco- Loss tangent tanδ (Tg) 3.16 3.04 3.40 2.29 2.90 2.942.10 elasticity Whether or not Formula (1) ∘ ∘ ∘ ∘ ∘ ∘ ∘ measurement issatisfied First storage modulus MPa 130 128 40.8 32.4 36.7 90.3 1.8 G′(Tg − 10° C.) Second storage modulus MPa 0.273 0.310 0.097 0.099 0.4450.118 0.149 G′ (Tg + 10° C.) Whether or not Formula (2) ∘ ∘ ∘ ∘ ∘ x x issatisfied (2) Sound insulating properties ∘ ∘ ∘ ∘ ∘ x x

EXPLANATION OF SYMBOLS

-   -   1: First layer    -   1 a: First surface    -   1 b: Second surface    -   2: Second layer    -   2 a: Outer surface    -   3: Third layer    -   3 a: Outer surface    -   11, 11A: Interlayer film    -   11 a: First surface    -   11 b: Second surface    -   21: First lamination glass member    -   22: Second lamination glass member    -   31, 31A: Laminated glass

1. An interlayer film for laminated glass having a one-layer structureor a two or more-layer structure, the interlayer film comprising a firstlayer having a glass transition temperature in dynamic viscoelasticitymeasurement of −30° C. or more and 10° C. or less, a loss tangent tan δof the first layer at Tg satisfying both of the following formula (1)and formula (2) when a glass transition temperature in unit ° C. of thefirst layer is referred to as Tg, storage modulus G′ of the first layerat Tg−10° C. is referred to as first storage modulus G′, and storagemodulus G′ of the first layer at Tg+10° C. is referred to as secondstorage modulus G′ in dynamic viscoelasticity measurement of the firstlayer:(Loss tangent tan δ of the first layer at Tg)≥1.55  (1)(Loss tangent tan δ of the first layer at Tg)=A×(first storage modulusG′/second storage modulus G′)+B  (2) in the above formula (2), A being0.003 or more and 0.04 or less, and B being 0.7 or more and 1.4 or less.2. The interlayer film for laminated glass according to claim 1, whereinthe first layer contains a compound having a softening point of 70° C.or more and 200° C. or less.
 3. The interlayer film for laminated glassaccording to claim 1, wherein the first layer contains a thermoplasticresin, or contains a cured product of a photocurable compound or amoisture-curable compound.
 4. The interlayer film for laminated glassaccording to claim 1, wherein the interlayer film is an interlayer filmfor laminated glass having a two or more-layer structure, the interlayerfilm comprises a second layer, and the second layer is arranged on afirst surface side of the first layer.
 5. The interlayer film forlaminated glass according to claim 4, wherein the interlayer film is aninterlayer film for laminated glass having a three or more-layerstructure, the interlayer film comprises a third layer, and the thirdlayer is arranged on a second surface side at the opposite side of thefirst surface of the first layer.
 6. The interlayer film for laminatedglass according to claim 5, wherein the first layer contains athermoplastic resin or contains a cured product of a curable compoundhaving a (meth)acryloyl group, the second layer contains a thermoplasticresin, and the third layer contains a thermoplastic resin.
 7. Theinterlayer film for laminated glass according to claim 6, wherein thefirst layer contains the thermoplastic resin, the thermoplastic resin inthe first layer is a polyvinyl acetal resin, the thermoplastic resin inthe second layer is a polyvinyl acetal resin, and the thermoplasticresin in the third layer is a polyvinyl acetal resin.
 8. The interlayerfilm for laminated glass according to claim 5, wherein the first layercontains a plasticizer, the second layer contains a plasticizer, and thethird layer contains a plasticizer.
 9. A laminated glass comprising: afirst lamination glass member; a second lamination glass member, and theinterlayer film for laminated glass according to claim 1, the interlayerfilm for laminated glass being arranged between the first laminationglass member and the second lamination glass member.